Method and apparatus for power and processing savings for positioning reference signals transmitted in beams

ABSTRACT

A mobile device supports positioning with positioning reference signals (PRS) on multiple beam by dividing the PRS processing into two separate modes, an acquisition mode and a tracking mode. In acquisition mode, the mobile device performs a fast scan of all of the beams from a base station transmitting PRS using less than the full set of resources for the PRS, i.e., less than the full bandwidth and/or less than the full number of repetitions of the PRS. The mobile device may select the best beams to use for positioning, e.g., based on signal strength metric. In tracking mode, the mobile device tracks the PRS from only the selected beams using the full set of resources for the PRS. The mobile device may return to acquisition mode after a predetermined number of positioning occasions or if the selected beams are no longer valid due to movement or change in conditions.

CLAIM OF PRIORITY UNDER 35 U.S.C. § 119

This application is a continuation of U.S. Ser. No. 18/312,513, entitled“METHOD AND APPARATUS FOR POWER AND PROCESSING SAVINGS FOR POSITIONINGREFERENCE SIGNALS TRANSMITTED IN BEAMS,” filed May 4, 2023, which is acontinuation of U.S. Ser. No. 17/523,815, entitled “METHOD AND APPARATUSFOR POWER AND PROCESSING SAVINGS FOR POSITIONING REFERENCE SIGNALSTRANSMITTED IN BEAMS,” filed Nov. 10, 2021, which is a continuation ofU.S. Ser. No. 17/135,461, entitled “METHOD AND APPARATUS FOR POWER ANDPROCESSING SAVINGS FOR POSITIONING REFERENCE SIGNALS TRANSMITTED INBEAMS,” filed Dec. 28, 2020, now U.S. Pat. No. 11,202,275, issued Dec.14, 2021, which is assigned to the assignee hereof and is incorporatedherein by reference in its entirety.

BACKGROUND Field

The subject matter disclosed herein relates to wireless communicationssystems, and more particularly to methods and apparatuses for positionlocation of a mobile device.

Relevant Background

The location of a mobile device, such as a cellular telephone, may beuseful or essential to a number of applications including emergencycalls, navigation, direction finding, asset tracking and Internetservice. The location of a mobile device may be estimated based oninformation gathered from various systems. In a cellular networkimplemented according to 4G (also referred to as Fourth Generation) LongTerm Evolution (LTE) radio access or 5G (also referred to as FifthGeneration) “New Radio” (NR), for example, a base station may transmit apositioning reference signal (PRS). A mobile device acquiring PRSstransmitted by different base stations may deliver signal-basedmeasurements to a location server, which may be part of an EvolvedPacket Core (EPC) or 5G Core Network (SGCN), for use in computing alocation estimate of the mobile device. For example, a UE may generatepositioning measurements from the downlink (DL) PRS such as ReferenceSignal Time Difference (RSTD), Reference Signal Received Power (RSRP),and reception and transmission (RX-TX) time difference measurements,which may be used in various positioning methods, such as TimeDifference of Arrival (TDOA), Angle of Departure (AoD), and multi-cellRound Trip Time (RTT). Alternatively, a mobile device may compute anestimate of its own location using various positioning methods. Otherposition methods that may be used for a mobile device include use of aGlobal Navigation Satellite System (GNSS) such as GPS, GLONASS orGalileo and use of Assisted GNSS (A-GNSS) where a network providesassistance data to a mobile decide to assist the mobile device inacquiring and measuring GNSS signals and/or in computing a locationestimate from the GNSS measurements.

With 5G NR cellular networks, base stations will utilize an array ofantenna elements for beamforming. With a large number of antennaelements, beamforming can be used to produce very narrow beams that canbe swept horizontally (azimuthally) and vertically (elevation) to form aspatial grid of beams. Implementation of positioning using beamtransmissions is progressing, e.g., for UE-based, UE-assisted,positioning techniques, as well as for Ul, DL, or UL and DL approachesto estimate Angle of Departure (AoD) and/or Angle of Arrival (AoA) atthe gNB. One important consideration is the power and processingrequired for positioning using PRS received in a plurality oftransmitted beams.

SUMMARY

A mobile device supports positioning with positioning reference signals(PRS) on multiple beam by may be dividing the PRS processing into twoseparate modes, an acquisition mode and a tracking mode. In theacquisition mode, the mobile device performs a fast scan of all of thebeams from a base station transmitting PRS using less than the full setof resources for the PRS, i.e., less than the full bandwidth and/or lessthan the full number of repetitions of the PRS. The mobile device mayselect the best beams to use for positioning, e.g., based on signalstrength metric. In the tracking mode, the mobile device tracks the PRSfrom only the selected beams using the full set of resources for thePRS. The mobile device may return to acquisition mode after apredetermined number of positioning occasions or if the selected beamsare no longer valid due to movement or change in conditions.

In one implementation, a method for supporting positioning of a mobiledevice in a wireless network performed by the mobile device, includesreceiving positioning reference signals (PRS) transmitted in a pluralityof beams from a base station using less than a full set of resources forthe PRS produced by each beam, wherein less than the full set ofresources for the PRS comprises less than a full bandwidth, less than afull number of repetitions in a positioning occasion, or a combinationthereof. The method may include selecting a predetermined number ofbeams from the plurality of beams. The method may include receiving thePRS from the selected beams using the full set of resources for the PRSproduced by each selected beam.

In one implementation, a mobile device configured for supportingpositioning of the mobile device in a wireless network, includes awireless transceiver configured to wirelessly communicate in thewireless network; at least one memory; and at least one processorcoupled to the wireless transceiver and the at least one memory. The atleast one processor may be configured to receive, using the wirelesstransceiver, positioning reference signals (PRS) transmitted in aplurality of beams from a base station using less than a full set ofresources for the PRS produced by each beam, wherein less than the fullset of resources for the PRS comprises less than a full bandwidth, lessthan a full number of repetitions in a positioning occasion, or acombination thereof. The at least one processor may be configured toselect a predetermined number of beams from the plurality of beams. Theat least one processor may be configured to receive, using the wirelesstransceiver, the PRS from the selected beams using the full set ofresources for the PRS produced by each selected beam.

In one implementation, a mobile device configured for supportingpositioning of the mobile device in a wireless network, includes meansfor receiving positioning reference signals (PRS) transmitted in aplurality of beams from a base station using less than a full set ofresources for the PRS produced by each beam, wherein less than the fullset of resources for the PRS comprises less than a full bandwidth, lessthan a full number of repetitions in a positioning occasion, or acombination thereof. The mobile device may include a means for selectinga predetermined number of beams from the plurality of beams. The mobiledevice may include a means for receiving the PRS from the selected beamsusing the full set of resources for the PRS produced by each selectedbeam.

In one implementation, a non-transitory computer readable storage mediumincluding program code stored thereon, the program code is operable toconfigure at least one processor in a mobile device for supportingpositioning of the mobile device in a wireless network, includes programcode to receive positioning reference signals (PRS) transmitted in aplurality of beams from a base station using less than a full set ofresources for the PRS produced by each beam, wherein less than the fullset of resources for the PRS comprises less than a full bandwidth, lessthan a full number of repetitions in a positioning occasion, or acombination thereof. The non-transitory computer readable storage mediummay include program code to select a predetermined number of beams fromthe plurality of beams. The non-transitory computer readable storagemedium may include program code to receive the PRS from the selectedbeams using the full set of resources for the PRS produced by eachselected beam.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary wireless communications system,according to various aspects of the disclosure.

FIGS. 2A and 2B illustrate example wireless network structures,according to various aspects of the disclosure.

FIG. 3 illustrates a block diagram of a design of base station and userequipment (UE), which may be one of the base stations and one of the UEsin FIG. 1 .

FIG. 4 shows a structure of an exemplary subframe sequence for apositioning reference signal (PRS).

FIG. 5 illustrates a nine different positioning reference signal (PRS)frame structures with varying symbol and comb values.

FIG. 6 illustrates an example of narrow beams that may be produced by anantenna panel for a base station.

FIG. 7 illustrates a positioning procedure performed by a UE and a basestation using PRS in transmit beams.

FIG. 8 is a graph illustrating multiple transmission beams and apositioning process using PRS in the beams.

FIG. 9 is a flow chart illustrating a positioning process in which thePRS processing is divided into two separate modes, an acquisition modeand a tracking mode.

FIG. 10 illustrates a graph of a simulated channel energy response (CER)for PRS that is processed using different fractions of the full set ofresources.

FIGS. 11A and 11B are graphs illustrating multiple transmission beamsand a positioning process using an acquisition mode that use less thanthe full set of resources for the PRS and a tracking mode.

FIG. 12 is a graph illustrating multiple transmission beams and apositioning process using an acquisition mode in which the fraction ofresources used for processing the PRS is increased in the acquisitionmode.

FIG. 13 is a graph illustrating multiple transmission beams and apositioning process using an acquisition mode in which the fraction ofresources used for processing the PRS is decreased in the acquisitionmode.

FIGS. 14A and 14B illustrate graphs showing the processing and powersavings through use of the acquisition and tracking modes.

FIG. 15 illustrates a schematic block diagram showing certain exemplaryfeatures of a mobile device enabled to support positioning using anacquisition mode and tracking mode.

FIG. 16 illustrates a flowchart of an exemplary method for supportingpositioning of a mobile device in a wireless network.

Elements are indicated by numeric labels in the figures with likenumbered elements in different figures representing the same element orsimilar elements. Different instances of a common element are indicatedby following a numeric label for the common element with a distinctnumeric suffix. In this case, a reference to the numeric label without asuffix indicates any instance of the common element. For example, FIG. 1contains four distinct network cells, labelled 110 a, 110 b, 110 c, and110 d. A reference to a cell 110 then corresponds to any of the cells110 a, 110 b, 110 c, and 110 d.

DETAILED DESCRIPTION

The terms “mobile device”, “mobile stations” (MS), “user equipment” (UE)and “target” are used interchangeably herein and may refer to a devicesuch as a cellular or other wireless communication device, personalcommunication system (PCS) device, personal navigation device (PND),Personal Information Manager (PIM), Personal Digital Assistant (PDA),laptop, smartphone, tablet or other suitable mobile device which iscapable of receiving wireless communication and/or navigation signals.The terms are also intended to include devices which communicate with apersonal navigation device (PND), such as by short-range wireless,infrared, wireline connection, or other connection—regardless of whethersatellite signal reception, assistance data reception, and/orposition-related processing occurs at the device or at the PND.

In addition, the terms MS, UE, “mobile device” or “target” are intendedto include all devices, including wireless and wireline communicationdevices, computers, laptops, etc., which are capable of communicationwith a server, such as via the Internet, WiFi, cellular wirelessnetwork, Digital Subscriber Line (DSL) network, packet cable network orother network, and regardless of whether satellite signal reception,assistance data reception, and/or position-related processing occurs atthe device, at a server, or at another device associated with thenetwork. Any operable combination of the above are also considered a“mobile device.”

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to represent the only configurationsin which the concepts described herein may be practiced. The detaileddescription includes specific details for the purpose of providing athorough understanding of the various concepts. However, it will beapparent to those skilled in the art that these concepts may bepracticed without these specific details. In some instances, well-knownstructures and components are shown in block diagram form in order toavoid obscuring such concepts.

The techniques described herein may be used for various wirelesscommunication networks such as code-division multiple access (CDMA),time-division multiple access (TDMA), frequency-division multiple access(FDMA), orthogonal frequency-division multiple access (OFDMA),single-carrier FDMA (SC-FDMA) and other networks. The terms “network”and “system” are often used interchangeably. A CDMA network mayimplement a radio technology such as Universal Terrestrial Radio Access(UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and othervariants of CDMA. cdma2000 covers IS-2000, IS-95 and IS-856 standards. ATDMA network may implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA network may implement a radiotechnology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are newreleases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSMare described in documents from an organization named “3rd GenerationPartnership Project” (3GPP). CDMA2000 and UMB are described in documentsfrom an organization named “3rd Generation Partnership Project 2”(3GPP2). The techniques described herein may be used for the wirelessnetworks and radio technologies mentioned above as well as otherwireless networks and radio technologies, such as a next generation(e.g., 5th Generation (5G) new radio (NR) operating in mmWave bands)network.

Beamformed transmissions are expected to be widespread deployed in 5G NRdeployments using spectrum under 6 GHz, e.g., sub-6, and mmWave, whichoperates using a spectrum above 24 GHz. For example, a base station witha large number of antenna elements may beamform to transmit beams in asets of beams over a range of horizontal (azimuthal) angles and vertical(elevation) angles to form a spatial grid of beams.

A UE may adopt a signaling/report according to a “Time of FirstDetected”/“Time of Arrival” metric, instead of L1-Reference SignalReceived Power (RSRP) metric. Thus, a beam of interest to a UE are thebeams from a base station with the first detected channel tap that isthe earliest and beams whose first detected channel tap is within apredetermined delay from the first detected tap of the beam withearliest first tap.

In 5G NR a base stations may transmit a downlink (DL) positioningreference signal (PRS) that is processed and measured by a UE fordetermining a location estimate of the UE. For example, a UE maygenerate positioning measurements from the DL PRS such as ReferenceSignal Time Difference (RSTD), Reference Signal Received Power (RSRP),and reception and transmission (RX-TX) time difference measurements,which may be used to determine a location estimate for the UE usingvarious positioning methods, such as Time Difference of Arrival (TDOA),Angle of Departure (AoD), and multi-cell Round Trip Time (RTT). In someimplementations, the UE may generate positioning measurements using DLPRS which may be sent to a remote location server to calculate alocation estimate for the UE in UE assisted positioning process or theUE may calculate its own location estimate in a UE based positioningprocess.

In 5G NR, PRS signals have been provided with expanded flexibility withrespect to LTE. For example, in 5G NR, PRS may be transmitted withmultiple symbol and Comb options per subframe and may be transmitted onmultiple subframes, i.e., repeated in the time domain for eachpositioning occasion. Moreover, multiple beams may transmit each PRS andthe beams may be repeated to improve performance. Further, multiple PRSoccasions may be used.

The expanded PRS flexibility, however, results in significantlyincreased power and processing requirements for receiving PRS.Improvements are needed to reduce memory and processing requirement forPRS reception using 5G NR.

Accordingly, in one implementation, positioning of a mobile device maybe supported by dividing the PRS processing into two separate modes,e.g., an acquisition mode and a tracking mode. In the acquisition mode,the mobile device performs a fast scan of all of the beams from a basestation transmitting PRS using less than the full set of resources forthe PRS. For example, the mobile device may acquire the PRS in each beamusing less than the full bandwidth of the PRS, less than the full numberof repetitions of the PRS, or a combination thereof. Using less than thefull set of resources for the PRS for each beam, the mobile device mayselect a predetermined number of beams to be used in the tracking mode.For example, the mobile device may use signal strength metrics, such asone or more of Signal to Noise Ratio (SNR), Reference Signal ReceivedPower (RSRP), or Reference Signal Received Quality (RSRQ), to selectbeams to be used in the tracking mode. In tracking mode, the mobiledevice tracks the PRS from the selected beams using the full set ofresources for the PRS produced by each selected beam. The mobile devicemay perform the desired positioning measurements using the PRS from theselected beams while in tracking mode.

By using less than the full set of resources for the PRS from each beamduring the acquisition mode, and using the full set of resources for thePRS only after a reduced number of beams have been selected fortracking, the mobile device may significantly reduce the power andprocessing requirements needed to process PRS for positioning.

FIG. 1 illustrates an exemplary wireless communications system 100. Thewireless communications system 100 (which may also be referred to as awireless wide area network (WWAN)) may include various base stations 102and various UEs 104. The base stations 102 may include macro cell basestations (high power cellular base stations) and/or small cell basestations (low power cellular base stations). In an aspect, the macrocell base station may include eNBs where the wireless communicationssystem 100 corresponds to an LTE network, or gNBs where the wirelesscommunications system 100 corresponds to a 5G network, or a combinationof both, and the small cell base stations may include femtocells,picocells, microcells, etc.

The base stations 102 may collectively form a RAN and interface with acore network 170 (e.g., an evolved packet core (EPC) or next generationcore (NGC)) through backhaul links 122, and through the core network 170to one or more location servers 172. Location server 172 may be internalor external to the core network 170. In some implementations, thelocation server 172 may be an E-SMLC in the case of LTE access, astandalone SMLC (SAS) in the case of UMTS access, an SMLC in the case ofGSM access, a SUPL Location Platform (SLP), or a Location ManagementFunction (LMF) in the case of 5G NR access. Additionally, oralternatively, the location server may be within the RAN and may beco-located with or part of a serving base station 102, which issometimes referred to as a Location Server Surrogate (LS S) 117. The LSS117 may replace the location server 172 or may operate in conjunctionwith the location server 172, e.g., performing some functions that wouldbe otherwise be performed by location server 172, e.g., to improvelatency. In addition to other functions, the base stations 102 mayperform functions that relate to one or more of transferring user data,radio channel ciphering and deciphering, integrity protection, headercompression, mobility control functions (e.g., handover, dualconnectivity), inter-cell interference coordination, connection setupand release, load balancing, distribution for non-access stratum (NAS)messages, NAS node selection, synchronization, RAN sharing, multimediabroadcast multicast service (MBMS), subscriber and equipment trace, RANinformation management (RIM), paging, positioning, and delivery ofwarning messages. The base stations 102 may communicate with each otherdirectly or indirectly (e.g., through the EPC/NGC) over backhaul links134, which may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. In an aspect, one or more cellsmay be supported by a base station 102 in each coverage area 110. A“cell” is a logical communication entity used for communication with abase station (e.g., over some frequency resource, referred to as acarrier frequency, component carrier, carrier, band, or the like), andmay be associated with an identifier (e.g., a physical cell identifier(PCID), a virtual cell identifier (VCID)) for distinguishing cellsoperating via the same or a different carrier frequency. In some cases,different cells may be configured according to different protocol types(e.g., machine-type communication (MTC), narrowband IoT (NB-IoT),enhanced mobile broadband (eMBB), or others) that may provide access fordifferent types of UEs. In some cases, the term “cell” may also refer toa geographic coverage area of a base station (e.g., a sector), insofaras a carrier frequency can be detected and used for communication withinsome portion of geographic coverage areas 110.

While neighboring macro cell base station 102 geographic coverage areas110 may partially overlap (e.g., in a handover region), some of thegeographic coverage areas 110 may be substantially overlapped by alarger geographic coverage area 110. For example, a small cell basestation 102′ may have a coverage area 110′ that substantially overlapswith the coverage area 110 of one or more macro cell base stations 102.A network that includes both small cell and macro cell base stations maybe known as a heterogeneous network. A heterogeneous network may alsoinclude home eNBs (HeNBs), which may provide service to a restrictedgroup known as a closed subscriber group (CSG).

The communication links 120 between the base stations 102 and the UEs104 may include UL (also referred to as reverse link) transmissions froma UE 104 to a base station 102 and/or downlink (DL) (also referred to asforward link) transmissions from a base station 102 to a UE 104. Thecommunication links 120 may use MIMO antenna technology, includingspatial multiplexing, beamforming, and/or transmit diversity. Thecommunication links 120 may be through one or more carrier frequencies.Allocation of carriers may be asymmetric with respect to DL and UL(e.g., more or less carriers may be allocated for DL than for UL).

The wireless communications system 100 may further include a wirelesslocal area network (WLAN) access point (AP) 150 in communication withWLAN stations (STAs) 152 via communication links 154 in an unlicensedfrequency spectrum (e.g., 5 GHz). When communicating in an unlicensedfrequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may performa clear channel assessment (CCA) prior to communicating in order todetermine whether the channel is available.

The small cell base station 102′ may operate in a licensed and/or anunlicensed frequency spectrum. When operating in an unlicensed frequencyspectrum, the small cell base station 102′ may employ LTE or 5Gtechnology and use the same 5 GHz unlicensed frequency spectrum as usedby the WLAN AP 150. The small cell base station 102′, employing LTE/5Gin an unlicensed frequency spectrum, may boost coverage to and/orincrease capacity of the access network. LTE in an unlicensed spectrummay be referred to as LTE-unlicensed (LTE-U), licensed assisted access(LAA), or MulteFire.

In 5G, the frequency spectrum in which wireless nodes (e.g., basestations 102, UEs 104) operate is divided into multiple frequencyranges, FR1 (from 4.1 GHz to 7.125 GHz), FR2 (from 24.25 GHz to 52.6GHz), and FR4 (between 52.6 GHz-114.25 GHz bands). The wirelesscommunications system 100 may further include a millimeter wave (mmW)base station 102, which may be a small cell base station, that mayoperate in mmW frequencies and/or near mmW frequencies in communicationwith a UE 104. Extremely high frequency (EHF) is part of the RF in theelectromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and awavelength between 1 millimeter and 10 millimeters. Radio waves in thisband may be referred to as a millimeter wave. Near mmW may extend downto a frequency of 3 GHz with a wavelength of 100 millimeters. The superhigh frequency (SHF) band extends between 3 GHz and 30 GHz, alsoreferred to as centimeter wave. Communications using the mmW/near mmWradio frequency band have high path loss and a relatively short range.The mmW base station 102 and the UE 104 may utilize beamforming(transmit and/or receive) over a mmW communication link 120 tocompensate for the extremely high path loss and short range. Further, itwill be appreciated that in alternative configurations, one or more basestations 102 may also transmit using mmW or near mmW and beamforming.Moreover, the mmW base station may operate in upper millimeter wavebands) e.g., between 24 GHz to 114 GHz, or some frequency allocationwithin that range, e.g., 24.25 GHz to 52.6 GHz or other ranges.Alternately, ultra wide bandwidth operation can also be in sub-THzfrequencies (beyond either 100 GHz or 275 GHz or 300 GHz depending onhow the sub-THz regime is defined). Accordingly, it will be appreciatedthat the foregoing illustrations are merely examples and should not beconstrued to limit the various aspects disclosed herein.

Transmit beamforming is a technique for focusing an RF signal in aspecific direction. Traditionally, when a network node (e.g., a basestation) broadcasts an RF signal, it broadcasts the signal in alldirections (omni-directionally). With transmit beamforming, the networknode determines where a given target device (e.g., a UE) is located(relative to the transmitting network node) and projects a strongerdownlink RF signal in that specific direction, thereby providing afaster (in terms of data rate) and stronger RF signal for the receivingdevice(s). To change the directionality of the RF signal whentransmitting, a network node can control the phase and relativeamplitude of the RF signal at each of the one or more transmitters thatare broadcasting the RF signal. For example, a network node may use anarray of antennas (referred to as a “phased array” or an “antennaarray”) that creates a beam of RF waves that can be “steered” to pointin different directions, without actually moving the antennas.Specifically, the RF current from the transmitter is fed to theindividual antennas with the correct phase relationship so that theradio waves from the separate antennas add together to increase theradiation in a desired direction, while cancelling to suppress radiationin undesired directions.

In receive beamforming, the receiver uses a receive beam to amplify RFsignals detected on a given channel. For example, the receiver canincrease the gain setting and/or adjust the phase setting of an array ofantennas in a particular direction to amplify (e.g., to increase thegain level of) the RF signals received from that direction. Thus, when areceiver is said to beamform in a certain direction, it means the beamgain in that direction is high relative to the beam gain along otherdirections, or the beam gain in that direction is the highest comparedto the beam gain in that direction of all other receive beams availableto the receiver. This results in a stronger received signal strength(e.g., reference signal received power (RSRP), reference signal receivedquality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) ofthe RF signals received from that direction.

The wireless communications system 100 may further include one or moreUEs, such as UE 190, that connects indirectly to one or morecommunication networks via one or more device-to-device (D2D)peer-to-peer (P2P) links. In the example of FIG. 1 , UE 190 has a D2DP2P link 192 with one of the UEs 104 connected to one of the basestations 102 (e.g., through which UE 190 may indirectly obtain cellularconnectivity) and a D2D P2P link 194 with WLAN STA 152 connected to theWLAN AP 150 (through which UE 190 may indirectly obtain WLAN-basedInternet connectivity). In an example, the D2D P2P links 192 and 194 maybe supported with any well-known D2D RAT, such as LTE Direct (LTE-D),WiFi Direct (WiFi-D), Bluetooth®, and so on.

The wireless communications system 100 may further include a UE 104 thatmay communicate with a macro cell base station 102 over a communicationlink 120 and/or the mmW base station 102 over a mmW communication link120. For example, the macro cell base station 102 may support a PCelland one or more SCells for a UE and the mmW base station 102 may supportone or more SCells for a UE.

FIG. 2A illustrates an example wireless network structure 200. Forexample, an NGC 210 (also referred to as a “5GC”) can be viewedfunctionally as control plane functions 214 (e.g., UE registration,authentication, network access, gateway selection, etc.) and user planefunctions 212, (e.g., UE gateway function, access to data networks, IProuting, etc.) which operate cooperatively to form the core network.User plane interface (NG-U) 213 and control plane interface (NG-C) 215connect the gNB 222 to the NGC 210 and specifically to the control planefunctions 214 and user plane functions 212. In an additionalconfiguration, an eNB 224 may also be connected to the NGC 210 via NG-C215 to the control plane functions 214 and NG-U 213 to user planefunctions 212. Further, eNB 224 may directly communicate with gNB 222via a backhaul connection 223. In some configurations, the New RAN 220may only have one or more gNBs 222, while other configurations includeone or more of both eNBs 224 and gNBs 222. Either gNB 222 or eNB 224 maycommunicate with UEs 204 (e.g., any of the UEs depicted in FIG. 1 ).Another optional aspect may include one or more location servers 230 a,230 b (sometimes collectively referred to as location server 230) (whichmay correspond to location server 172), which may be in communicationwith the control plane functions 214 and user plane functions 212,respectively, in the NGC 210 to provide location assistance for UEs 204.The location server 230 can be implemented as a plurality of separateservers (e.g., physically separate servers, different software moduleson a single server, different software modules spread across multiplephysical servers, etc.), or alternately may each correspond to a singleserver. The location server 230 can be configured to support one or morelocation services for UEs 204 that can connect to the location server230 via the core network, NGC 210, and/or via the Internet (notillustrated). Further, the location server 230 may be integrated into acomponent of the core network, or alternatively may be external to thecore network, e.g., in the RAN 220. Additionally, a Location ServerSurrogate (LSS) (such as LSS 117 shown in FIG. 1 ) may be located in theRAN 220, e.g., co-located with a gNB 222, and may perform one or morelocation management functions.

FIG. 2B illustrates another example wireless network structure 250. Forexample, an NGC 260 (also referred to as a “5GC”) can be viewedfunctionally as control plane functions, provided by an access andmobility management function (AMF) 264, user plane function (UPF) 262, asession management function (SMF) 266, SLP 268, and an LMF 270, whichoperate cooperatively to form the core network (i.e., NGC 260). Userplane interface 263 and control plane interface 265 connect the ng-eNB224 to the NGC 260 and specifically to UPF 262 and AMF 264,respectively. In an additional configuration, a gNB 222 may also beconnected to the NGC 260 via control plane interface 265 to AMF 264 anduser plane interface 263 to UPF 262. Further, eNB 224 may directlycommunicate with gNB 222 via the backhaul connection 223, with orwithout gNB direct connectivity to the NGC 260. In some configurations,the New RAN 220 may only have one or more gNBs 222, while otherconfigurations include one or more of both ng-eNBs 224 and gNBs 222.Either ng-gNB 222 or eNB 224 may communicate with UEs 204 (e.g., any ofthe UEs depicted in FIG. 1 ). The base stations of the New RAN 220communicate with the AMF 264 over the N2 interface and the UPF 262 overthe N3 interface.

The functions of the AMF include registration management, connectionmanagement, reachability management, mobility management, lawfulinterception, transport for session management (SM) messages between theUE 204 and the SMF 266, transparent proxy services for routing SMmessages, access authentication and access authorization, transport forshort message service (SMS) messages between the UE 204 and the shortmessage service function (SMSF) (not shown), and security anchorfunctionality (SEAF). The AMF also interacts with the authenticationserver function (AUSF) (not shown) and the UE 204, and receives theintermediate key that was established as a result of the UE 204authentication process. In the case of authentication based on a UMTS(universal mobile telecommunications system) subscriber identity module(USIM), the AMF retrieves the security material from the AUSF. Thefunctions of the AMF also include security context management (SCM). TheSCM receives a key from the SEAF that it uses to derive access-networkspecific keys. The functionality of the AMF also includes locationservices management for regulatory services, transport for locationservices messages between the UE 204 and the location managementfunction (LMF) 270 (which may correspond to location server 172), aswell as between the New RAN 220 and the LMF 270, evolved packet system(EPS) bearer identifier allocation for interworking with the EPS, and UE204 mobility event notification. In addition, the AMF also supportsfunctionalities for non-Third Generation Partnership Project (3GPP)access networks.

Functions of the UPF include acting as an anchor point forintra-/inter-RAT mobility (when applicable), acting as an externalprotocol data unit (PDU) session point of interconnect to the datanetwork (not shown), providing packet routing and forwarding, packetinspection, user plane policy rule enforcement (e.g., gating,redirection, traffic steering), lawful interception (user planecollection), traffic usage reporting, quality of service (QoS) handlingfor the user plane (e.g., UL/DL rate enforcement, reflective QoS markingin the DL), UL traffic verification (service data flow (SDF) to QoS flowmapping), transport level packet marking in the UL and DL, DL packetbuffering and DL data notification triggering, and sending andforwarding of one or more “end markers” to the source RAN node.

The functions of the SMF 266 include session management, UE Internetprotocol (IP) address allocation and management, selection and controlof user plane functions, configuration of traffic steering at the UPF toroute traffic to the proper destination, control of part of policyenforcement and QoS, and downlink data notification. The interface overwhich the SMF 266 communicates with the AMF 264 is referred to as theN11 interface.

Another optional aspect may include an LMF 270, which may be incommunication with the NGC 260 to provide location assistance for UEs204. The LMF 270 can be implemented as a plurality of separate servers(e.g., physically separate servers, different software modules on asingle server, different software modules spread across multiplephysical servers, etc.), or alternately may each correspond to a singleserver. The LMF 270 can be configured to support one or more locationservices for UEs 204 that can connect to the LMF 270 via the corenetwork, NGC 260, and/or via the Internet (not illustrated).

FIG. 3 shows a block diagram of a design 300 of base station 102 and UE104, which may be one of the base stations and one of the UEs in FIG. 1. Base station 102 may be equipped with T antennas 334 a through 334 t,and UE 104 may be equipped with R antennas 352 a through 352 r, where ingeneral T≥1 and R≥1.

At base station 102, a transmit processor 320 may receive data from adata source 312 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 320 may also process system information (e.g., for semi-staticresource partitioning information (SRPI) and/or the like) and controlinformation (e.g., CQI requests, grants, upper layer signaling, and/orthe like) and provide overhead symbols and control symbols. Transmitprocessor 320 may also generate reference symbols for reference signals(e.g., the cell-specific reference signal (CRS)) and synchronizationsignals (e.g., the primary synchronization signal (PSS) and secondarysynchronization signal (SSS)). A transmit (TX) multiple-inputmultiple-output (MIMO) processor 330 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, the overheadsymbols, and/or the reference symbols, if applicable, and may provide Toutput symbol streams to T modulators (MODs) 332 a through 332 t. Eachmodulator 332 may process a respective output symbol stream (e.g., forOFDM and/or the like) to obtain an output sample stream. Each modulator332 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal. Tdownlink signals from modulators 332 a through 332 t may be transmittedvia T antennas 334 a through 334 t, respectively. According to variousaspects described in more detail below, the synchronization signals canbe generated with location encoding to convey additional information.

At UE 104, antennas 352 a through 352 r may receive the downlink signalsfrom base station 102 and/or other base stations and may providereceived signals to demodulators (DEMODs) 354 a through 354 r,respectively. Each demodulator 354 may condition (e.g., filter, amplify,down convert, and digitize) a received signal to obtain input samples.Each demodulator 354 may further process the input samples (e.g., forOFDM and/or the like) to obtain received symbols. A MIMO detector 356may obtain received symbols from all R demodulators 354 a through 354 r,perform MIMO detection on the received symbols if applicable, andprovide detected symbols. A receive processor 358 may process (e.g.,demodulate and decode) the detected symbols, provide decoded data for UE104 to a data sink 360, and provide decoded control information andsystem information to a controller/processor 380. A channel processormay determine reference signal received power (RSRP), received signalstrength indicator (RSSI), reference signal received quality (RSRQ),channel quality indicator (CQI), and/or the like. In some aspects, oneor more components of UE 104 may be included in a housing.

On the uplink, at UE 104, a transmit processor 364 may receive andprocess data from a data source 362 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) fromcontroller/processor 380. Transmit processor 364 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 364 may be precoded by a TX MIMO processor 366 ifapplicable, further processed by modulators 354 a through 354 r (e.g.,for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to basestation 102. At base station 102, the uplink signals from UE 104 andother UEs may be received by antennas 334, processed by demodulators332, detected by a MIMO detector 336 if applicable, and furtherprocessed by a receive processor 338 to obtain decoded data and controlinformation sent by UE 104. Receive processor 338 may provide thedecoded data to a data sink 339 and the decoded control information tocontroller/processor 340. Base station 102 may include communicationunit 344 and communicate to a network controller, such as locationserver 172 via communication unit 344, which may include one or moreintervening elements. Location server 172 may include communication unit394, controller/processor 390, and memory 392.

Controller/processor 340 of base station 102, controller/processor 380of UE 104, controller 390 of location server 172, which may be locationserver 172, and/or any other component(s) of FIG. 3 may perform one ormore techniques as described in more detail elsewhere herein. Forexample, controller/processor 380 of UE 104, controller 390 of locationserver 172, controller/processor 340 of base station 102, and/or anyother component(s) of FIG. 3 may perform or direct operations of, forexample, processes 900 and 1600 of FIGS. 9 and 16 , and/or otherprocesses as described herein. Memories 342, 382, and 392 may store dataand program codes for base station 102, UE 104, and location server 172,respectively. In some aspects, memory 342 and/or memory 382 and/ormemory 392 may comprise a non-transitory computer-readable mediumstoring one or more instructions for wireless communication. Forexample, the one or more instructions, when executed by one or moreprocessors of the UE 104, location server 172, and/or base station 102,may perform or direct operations of, for example, processes 900 and 1600of FIGS. 9 and 16 and/or other processes as described herein. Ascheduler 346 may schedule UEs for data transmission on the downlinkand/or uplink.

As indicated above, FIG. 3 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 3 .

In particular implementations, the UE 104 may have circuitry andprocessing resources capable of obtaining location related measurements(also referred to as location measurements), such as measurements forsignals received from GPS or other Satellite Positioning Systems(SPS's), measurements for cellular transceivers such as base stations102, and/or measurements for local transceivers. UE 104 may further havecircuitry and processing resources capable of computing a position fixor estimated location of UE 104 based on these location relatedmeasurements. In some implementations, location related measurementsobtained by UE 104 may be transferred to a location server, such as thelocation server 172, location servers 230 a, 230 b, or LMF 270, afterwhich the location server may estimate or determine a location for UE104 based on the measurements.

Location related measurements obtained by UE 104 may includemeasurements of signals received from satellite vehicles (SVs) that arepart of an SPS or Global Navigation Satellite System (GNSS) such as GPS,GLONASS, Galileo or Beidou and/or may include measurements of signalsreceived from terrestrial transmitters fixed at known locations (e.g.,such as base station 102 or other local transceivers). UE 104 or aseparate location server (e.g. location server 172) may then obtain alocation estimate for the UE 104 based on these location relatedmeasurements using any one of several position methods such as, forexample, GNSS, Assisted GNSS (A-GNSS), Advanced Forward LinkTrilateration (AFLT), Time Difference Of Arrival (TDOA), Enhanced CellID (ECID), TDOA, AoA, AoD, multi-RTT, or combinations thereof. In someof these techniques (e.g. A-GNSS, AFLT and TDOA), pseudoranges or timingdifferences may be measured by UE 104 relative to three or moreterrestrial transmitters fixed at known locations or relative to four ormore SVs with accurately known orbital data, or combinations thereof,based at least in part, on pilot signals, positioning reference signals(PRS) or other positioning related signals transmitted by thetransmitters or SVs and received at the UE 104. Here, location servers,such as location server 172, location servers 230 a, 230 b, or LMF 270may be capable of providing positioning assistance data to UE 104including, for example, information regarding signals to be measured byUE 104 (e.g., expected signal timing, signal coding, signal frequencies,signal Doppler), locations and/or identities of terrestrialtransmitters, and/or signal, timing and orbital information for GNSS SVsto facilitate positioning techniques such as A-GNSS, AFLT, TDOA, AoA,AoD, multi-RTT, and ECID. The facilitation may include improving signalacquisition and measurement accuracy by UE 104 and/or, in some cases,enabling UE 104 to compute its estimated location based on the locationmeasurements. For example, a location server may comprise an almanac(e.g., a Base Station Almanac (BSA)) which indicates the locations andidentities of cellular transceivers and transmitters (e.g. base stations102) and/or local transceivers and transmitters in a particular regionor regions such as a particular venue, and may further containinformation descriptive of signals transmitted by these transceivers andtransmitters such as signal power, signal timing, signal bandwidth,signal coding and/or signal frequency. In the case of ECID, a UE 104 mayobtain measurements of signal strength (e.g. received signal strengthindication (RSSI) or reference signal received power (RSRP)) for signalsreceived from cellular transceivers (e.g., base stations 102) and/orlocal transceivers and/or may obtain a signal to noise ratio (S/N), areference signal received quality (RSRQ), or a round trip signalpropagation time (RTT) between UE 104 and a cellular transceiver (e.g.,base stations 102) or a local transceiver. A UE 104 may transfer thesemeasurements to a location server, to determine a location for UE 104,or in some implementations, UE 104 may use these measurements togetherwith positioning assistance data (e.g. terrestrial almanac data or GNSSSV data such as GNSS Almanac and/or GNSS Ephemeris information) receivedfrom the location server to determine a location for UE 104.

An estimate of a location of a UE 104 may be referred to as a location,location estimate, location fix, fix, position, position estimate orposition fix, and may be geodetic, thereby providing locationcoordinates for the UE 104 (e.g., latitude and longitude) which may ormay not include an altitude component (e.g., height above sea level,height above or depth below ground level, floor level or basementlevel). Alternatively, a location of the UE 104 may be expressed as acivic location (e.g., as a postal address or the designation of somepoint or small area in a building such as a particular room or floor). Alocation of a UE 104 may also include an uncertainty and may then beexpressed as an area or volume (defined either geodetically or in civicform) within which the UE 104 is expected to be located with some givenor default probability or confidence level (e.g., 67% or 95%). Alocation of a UE 104 may further be an absolute location (e.g. definedin terms of a latitude, longitude and possibly altitude and/oruncertainty) or may be a relative location comprising, for example, adistance and direction or relative X, Y (and Z) coordinates definedrelative to some origin at a known absolute location. In the descriptioncontained herein, the use of the term location may comprise any of thesevariants unless indicated otherwise. Measurements (e.g. obtained by UE104 or by another entity such as base station 102) that are used todetermine (e.g. calculate) a location estimate for UE 104 may bereferred to as measurements, location measurements, location relatedmeasurements, positioning measurements or position measurements and theact of determining a location for the UE 104 may be referred to aspositioning of the UE 104 or locating the UE 104.

FIG. 4 shows a structure of an exemplary subframe sequence 400 withpositioning reference signal (PRS) positioning occasions. Subframesequence 400 may be applicable to the broadcast of PRS signals from abase station (e.g., any of the base stations described herein) or othernetwork node. The subframe sequence 400 may be used in LTE systems, andthe same or similar subframe sequence may be used in other communicationtechnologies/protocols, such as 5G NR. For example, with 5G NR, theresource grid is nearly identical to that used with LTE, but thephysical dimensions, e.g., subcarrier spacing, number of OFDM symbolswithin a radio frame) varies in NR depending on the numerology.

In FIG. 4 , time is represented horizontally (e.g., on the X axis) withtime increasing from left to right, while frequency is representedvertically (e.g., on the Y axis) with frequency increasing (ordecreasing) from bottom to top. As shown in FIG. 4 , downlink and uplinkradio frames 410 may be of 10 millisecond (ms) duration each. Fordownlink frequency division duplex (FDD) mode, radio frames 410 areorganized, in the illustrated example, into ten subframes 412 of 1 msduration each. Each subframe 412 comprises two slots 414, each of, forexample, 0.5 ms duration.

In the frequency domain, the available bandwidth may be divided intouniformly spaced orthogonal subcarriers 416 (also referred to as “tones”or “bins”). For example, for a normal length cyclic prefix (CP) using,for example, 15 kHz spacing, subcarriers 416 may be grouped into a groupof twelve (12) subcarriers. A resource of one OFDM symbol length in thetime domain and one subcarrier in the frequency domain (represented as ablock of subframe 412) is referred to as a resource element (RE). Eachgrouping of the 12 subcarriers 416 and the 14 OFDM symbols is termed aresource block (RB) and, in the example above, the number of subcarriersin the resource block may be written as N_(SC) ^(RB)=12. For a givenchannel bandwidth, the number of available resource blocks on eachchannel 422, which is also called the transmission bandwidthconfiguration 422, is indicated as N_(RB) ^(DL). For example, for a 3MHz channel bandwidth in the above example, the number of availableresource blocks on each channel 422 is given by N_(RB) ^(DL)=15. Notethat the frequency component of a resource block (e.g., the 12subcarriers) is referred to as a physical resource block (PRB).

A base station may transmit radio frames (e.g., radio frames 410), orother physical layer signaling sequences, supporting PRS signals (i.e. adownlink (DL) PRS) according to frame configurations either similar to,or the same as that, shown in FIG. 4 , which may be measured and usedfor a UE (e.g., any of the UEs described herein) position estimation.Other types of wireless nodes (e.g., a distributed antenna system (DAS),remote radio head (RRH), UE, AP, etc.) in a wireless communicationsnetwork may also be configured to transmit PRS signals configured in amanner similar to (or the same as) that depicted in FIG. 4 .

A collection of resource elements that are used for transmission of PRSsignals is referred to as a “PRS resource.” The collection of resourceelements can span multiple PRBs in the frequency domain and N (e.g., 1or more) consecutive symbol(s) within a slot 414 in the time domain. Forexample, the cross-hatched resource elements in the slots 414 may beexamples of two PRS resources. A “PRS resource set” is a set of PRSresources used for the transmission of PRS signals, where each PRSresource has a PRS resource identifier (ID). In addition, the PRSresources in a PRS resource set are associated with the sametransmission-reception point (TRP). A PRS resource ID in a PRS resourceset is associated with a single beam transmitted from a single TRP(where a TRP may transmit one or more beams). Note that this does nothave any implications on whether the TRPs and beams from which signalsare transmitted are known to the UE.

PRS may be transmitted in special positioning subframes that are groupedinto positioning occasions. A PRS occasion is one instance of aperiodically repeated time window (e.g., consecutive slot(s)) where PRSare expected to be transmitted. Each periodically repeated time windowcan include a group of one or more consecutive PRS occasions. Each PRSoccasion can comprise a number N_(PRS) of consecutive positioningsubframes. The PRS positioning occasions for a cell supported by a basestation may occur periodically at intervals, denoted by a number T_(PRS)of milliseconds or subframes. As an example, FIG. 4 illustrates aperiodicity of positioning occasions where N_(PRS) equals 4 418 andT_(PRS) is greater than or equal to 20 420. In some aspects, T_(PRS) maybe measured in terms of the number of subframes between the start ofconsecutive positioning occasions. Multiple PRS occasions may beassociated with the same PRS resource configuration, in which case, eachsuch occasion is referred to as an “occasion of the PRS resource” or thelike.

A PRS may be transmitted with a constant power. A PRS can also betransmitted with zero power (i.e., muted). Muting, which turns off aregularly scheduled PRS transmission, may be useful when PRS signalsbetween different cells overlap by occurring at the same or almost thesame time. In this case, the PRS signals from some cells may be mutedwhile PRS signals from other cells are transmitted (e.g., at a constantpower). Muting may aid signal acquisition and time of arrival (TOA) andreference signal time difference (RSTD) measurement, by UEs, of PRSsignals that are not muted (by avoiding interference from PRS signalsthat have been muted). Muting may be viewed as the non-transmission of aPRS for a given positioning occasion for a particular cell. Mutingpatterns (also referred to as muting sequences) may be signaled (e.g.,using the LTE positioning protocol (LPP)) to a UE using bit strings. Forexample, in a bit string signaled to indicate a muting pattern, if a bitat position j is set to ‘0’, then the UE may infer that the PRS is mutedfor a j^(th) positioning occasion.

To further improve hearability of PRS, positioning subframes may below-interference subframes that are transmitted without user datachannels. As a result, in ideally synchronized networks, PRS may beinterfered with by other cells' PRS with the same PRS pattern index(i.e., with the same frequency shift), but not from data transmissions.The frequency shift may be defined as a function of a PRS ID for a cellor other transmission point (TP) (denoted as N_(ID) ^(PRS)) or as afunction of a physical cell identifier (PCI) (denoted as N_(ID) ^(cell))if no PRS ID is assigned, which results in an effective frequency re-usefactor of six (6).

To also improve hearability of a PRS (e.g., when PRS bandwidth islimited, such as with only six resource blocks corresponding to 1.4 MHzbandwidth), the frequency band for consecutive PRS positioning occasions(or consecutive PRS subframes) may be changed in a known and predictablemanner via frequency hopping. In addition, a cell supported by a basestation may support more than one PRS configuration, where each PRSconfiguration may comprise a distinct frequency offset (vshift), adistinct carrier frequency, a distinct bandwidth, a distinct codesequence, and/or a distinct sequence of PRS positioning occasions with aparticular number of subframes (N_(PRS)) per positioning occasion and aparticular periodicity (T_(PRS)). In some implementation, one or more ofthe PRS configurations supported in a cell may be for a directional PRSand may then have additional distinct characteristics, such as adistinct direction of transmission, a distinct range of horizontalangles, and/or a distinct range of vertical angles.

A PRS configuration, as described above, including the PRStransmission/muting schedule, is signaled to the UE to enable the UE toperform PRS positioning measurements. The UE is not expected to blindlyperform detection of PRS configurations.

FIG. 5 illustrates nine different DL positioning reference signal (PRS)frame structure options available in 5G NR, where each PRS framestructure in FIG. 5 illustrates the transmission of a DL PRS with ashaded square. A DL PRS resource may span within a slot 2, 4, 6, 12consecutive symbols with a staggered pattern of 2, 4, 6, or 12 in thefrequency-domain. The PRS frame structures are identified with thenumber of symbols of the subframe in each sub-carrier, during which PRSare transmitted. The term “symbol” is well defined in LTE and NR as acollection of sub-carriers transmitted over some common and fixed timeduration. The PRS frame structures are further identified with thestaggering of the frequency of transmission in each symbol, referred toas Comb. For example, the top left PRS frame structure uses 2 symbols(with a DL-PRS-ResourceSymbolOffset of 3), where only every othersub-carrier is utilized within each symbol, i.e., Comb-2. The bottomleft PRS frame structure uses 6 symbols (DL-PRS-ResourceSymbolOffset of2), and only every sixth sub-carrier is utilized within each symbol,i.e., Comb-6. Thus, the top row of FIG. 5 illustrate three PRS framestructures with 2, 4, and 6 symbols, all of which have a Comb 2structure, the middle row illustrates three PRS frame structures having12, 4, and 12 symbols and having Comb-2, Comb-4 and Comb-4 structures,respectively, and the bottom row illustrates three PRS frame structureswith 6, 12, and 12 symbols having Comb-6, Comb-6, and Comb-12structures, respectively.

Thus, for each transmitted PRS, the PRS is repeated over a number ofsubframes in each positioning occasion. Additionally, the PRS istransmitted with a bandwidth that is the full frequency spectrum, e.g.,all subcarrier frequencies. During reception of the PRS, the UE 104tunes the radio signal receiver to the bandwidth of the PRS andreceives, processes, and integrates over all repetitions of the PRS toproduce the PRS measurement for the sub-frame or frame.

FIG. 6 illustrates an example of narrow beams that may be produced by anantenna panel 602 for a base station 102. The antenna panel 602 includesa number of separate antennas which are provided RF current from thetransmitter with the correct phase relationship so that the radio wavesfrom the separate antennas add together to increase the radiation in adesired direction, while cancelling to suppress radiation in undesireddirections, to produce a beam. The beam can be steered to point indifferent directions, e.g., changing the azimuth angle and elevationangle, without moving the antenna panel 602. FIG. 6 , for example,illustrates the antenna panel 602 in the center of a sphere 600 showingazimuth angles from 0°, ±90°, to 180°, and elevation angles from 0°,±90°, to 180°. The antenna panel 602 may be controlled to produce beamsat various angles, illustrated as beams 604, 606, and 608. In general,the antenna panel 602 may produce an azimuth span of 120° and anelevation span of 60°. By increasing the number of individual antennaspresent in the antenna panel 602, the width of the beams produced may bereduced. Initial link acquisition at base stations may be performed overbeamformed transmissions in Secondary Synchronization Blocks (SSBs).Beam refinement beyond the SSB stage is either performed over channelstate information reference signals (CSI-RSs) or sounding referencesignals (SRSs). These stages lead to refined beams at both the basestation and user ends. Each beam transmitted by a base station mayinclude PRS.

FIG. 7 , by way of example, illustrates a positioning procedure 700performed by a UE 104 and a base station 102 using PRS in transmitbeams. The base station 102, which may be a gNB, transmits PRS resourcesin a beam-sweeping manner, illustrated as beams 702, 704, and 706,labeled as PRS #1, PRS #2, and PRS #3, respectively. The UE 104 mayreceive one or more PRS resource in beams 702, 704, and 706, using abeamformed receive beam 712. For example, in time based positioningprocedures, such as TDOA, RTT, etc., the UE 104 may use PRS received ina plurality of beams, while angle based measurements, such as AoD, thePRS 706 most closely aligned with the line of sight (LOS) 710 betweenthe base station 102 and the UE 104 may be used. During positioningmeasurements, PRS received from more than one base station may be used.

In UE-assisted mode, the UE 104 may report the positioning measurementfor one or more received PRS through LPP protocol to the locationserver, e.g., location server 172, which may calculate an estimatedposition of the UE 104. In UE-based mode, the UE 104 may use assistancedata provided by the location server 172, which may include positioninginformation such as the positions of base stations, along with thepositioning measurements, to calculate an estimated position of the UE104.

Relative to LTE PRS implementations, the flexibility in PRS signalingprovided in 5G NR, including multiple symbol and Comb options persubframe, repetitions of the PRS transmission in multiple subframes, andon multiple beams, significantly increases the processing, e.g., millioninstructions per second (MIPS), memory, and power requirements. Forexample, Table 1 below illustrates the processing requirements for oncecell for different technologies that use different configurations, e.g.,illustrated as resource blocks (RBs), Inverse Fourier Fast Transform(IFFT) operations, and number of beams.

TABLE 1 Multiplier- Accumulator Technology (MAC) operations NormalizedConfiguration LTE 20360 1 100 RB, IFFT = 2048 5G - FR1 630272 30.9 272RB, IFFT = 8192, beam = 8 5G - FR2 4954112 243.3 264 RB, IFFT = 8192,beam = 64

As can be seen in Table 1, the requirements for processing PRS, andthus, the required power, for 5G FR1 or 5G FR2 is significantly greaterthan processing PRS with LTE.

FIG. 8 , by way of example, is a graph 800 illustrating 8 transmissionbeams B1, B2, B3, B4, B5, B6, B7, and B8 produced by a base station inFR1. Each beam includes PRS provided over multiple positioningoccasions, e.g., at 0, 160, 320, 480, 640, and 800 ms. Each PRS occasionincludes 1 subframe (N_(PRS)=1) of PRS and two repetitions, i.e., thenumber of times the PRS resource (subframe) is transmitted (which may bebetween, e.g., 1 and 32), illustrated as two bars in each positioningoccasion. By way of example, the PRS may use the two symbols with Comb-2option and may have 272 resource blocks (RBs), and require 4 k, 8 k, or16 k operations, depending on the performance requirements. With thisconfiguration, for a single cell, the UE needs to decode 2 symbol*8beam*beam repetitions*N_(PRS), over the full bandwidth of the PRS, whichis a large processing requirement, particularly if the PRS BW is high.

As illustrated in FIG. 8 in the first positioning occasion, the UE 104may process all 8 beams over the full set of resources used by the PRSon each beam, including the full bandwidth and the full number ofrepetitions. The UE 104 may select the best beams amongst the 8 beamsand in future positioning occasions may process only the selected beams,e.g., beams B1, B5, and B6, for the remaining positioning occasions,e.g., at 160, 320, 480, 640, and 800 ms. Even though a reduced number ofbeams are processed in subsequent positioning occasions, the processorand power requirements for processing the PRS over the full set ofresources available for the PRS on each beam may be exceedingly largeand it is desirable to reduce the processing requirements.

Accordingly, in one implementation, the UE 104 may divide the PRSprocessing into two separate modes, e.g., an acquisition mode and atracking mode. During the acquisition mode, the UE 104 performs a fastscan of all of the beams from a base station 102 transmitting PRS usingless than the full set of resources for the PRS, while in the trackingmode the UE 104 processes the full set of resources for the PRS, but fora reduced number of beams.

FIG. 9 is a flow chart illustrating a positioning process 900 that maybe employed by the UE 104 in which the PRS processing is divided intotwo separate modes, e.g., an acquisition mode and a tracking mode.

As illustrated at block 902, a determination is made whether the UE 104is in acquisition mode or tracking mode. Acquisition mode 901, forexample, is performed during an initial positioning occasion or afterbeing in tracking mode for a predetermined number of occasions or thereis an indication that the selection of beams from the initialacquisition may no longer be valid, e.g., if there is an indication thatthe UE 104 may have moved or conditions have changed.

At block 904, the UE 104 initializes the set of resources that will beused for processing the PRS for each beam in the acquisition mode 901.The set of resources used in acquisition mode 901 is less than the fullset of resources for the PRS produced by each beam. The UE 104, forexample, may be aware of the full set of resources for the PRS for eachbeam, including the full bandwidth and full number of repetitions,through assistance data received from the location server 172. The UE104 may initialize the set of resources by selecting a fraction of thefull bandwidth, a fraction of the full number of repetitions, or acombination thereof, to be used for receiving and processing the PRS. Byway of example, the UE 104 may select to use ½, ¼, ⅛, 1/16, etc., of thefull bandwidth. The receiver, for example may be tuned to receive afraction of the full bandwidth of the PRS while in acquisition mode.Similarly, the UE 104 may additionally or alternatively select to use afraction or some portion of the full number of repetitions, e.g., ½, ⅓,⅔, ¼, ¾ etc., as long as at least one repetition (e.g., one PRSresource) is transmitted. For example, where there are 2 repetitions,i.e., the PRS resource is transmitted two times, the UE 104 may selectto use 1 repetition (only the initial PRS resource is transmitted) or 2repetitions, while if there are 4 repetitions, the UE 104 may select touse 1, 2, 3, or 4 repetitions, where the resulting number of transmittedPRS resources is a whole number, i.e., in the time domain, at least onecomplete PRS resource (subframe) is transmitted. The processors in theUE 104, thus, may be configured to receive and integrate over less thanthe full number of repetitions of the PRS while in acquisition mode.

At block 906, the UE 104 receives and processes the PRS signalsaccording to the initialized set of resources and determines a signalstrength metric for each beam in the plurality of beams. For example,the UE 104 may receive the PRS by tuning the radio signal receiver tothe initialized fraction of the full bandwidth for the PRS on each beam,e.g., ¼ of the full bandwidth of the PRS. The UE 104 may additionally oralternatively receive and integrate over the fraction of the full numberof repetitions for the PRS on each beam, e.g., 1, ½, ⅓, or ¼ of the fullnumber of repetitions in the PRS. The UE 104 may measure one or moresignal strength metrics, such as SNR, RSRP, or RSRQ for the received PRSfor each beam. For example, in one implementation, the channel energyresponse may be calculated and used to determine the peak SNR.

FIG. 10 , by way of example, illustrates a graph 1000 of a simulatedchannel energy response (CER) for PRS that is processed using differentfractions of the full set of resources (different fractions of the fullbandwidth). For example, graph 1000 illustrates the CER 1002 for a PRSwith 68 RBs and 2048 IFFT (corresponding to a ¼ of the bandwidth), a CER1004 for a PRS with 138 RB and 4096 IFFT (corresponding to a ½ of thebandwidth), and a CER 1006 for a PRS with 272 RB and 8192 IFFT(corresponding to the full bandwidth). The noise floors 1012, 1014 and1016 associated with each of the CERs 1002, 1004, and 1006, respectivelyis also illustrated. The peak SNR is determined based on the differencebetween the CER value at tap 0 and the noise floor. For example, CER1002 has a peak SNR of 29 dB, CER 1004 has a peak SNR of 32 dB, and CER1006 has a peak SNR of 35 dB. Thus, as can be seen, by reducing the setof resources used to process the PRS, there is a measurable performanceloss in the peak SNR. For example, there is an approximate 3 dB loss forevery half bandwidth reduction. Similarly, reducing the set of resourcesused to process the PRS results in a measurable performance loss inother signal strength metrics, such as RSRP, or RSRQ.

Referring back to FIG. 9 , at block 908, the one or more signal strengthmetrics for each beam (i) may be compared to predetermined thresholdscorresponding to the one or more signal strength metrics to determine ifa predetermined number M of beams have signal strength metrics thatexceed the predetermined thresholds and whether less than the full setof resources were used to process the PRS. The predetermined thresholdused for the comparison to the signal strength metrics may beempirically selected based on the sensitivity of the radio signalreceiver. For example, referring to FIG. 10 , in some implementations,an SNR threshold of 25 dB may be used with some devices, but otherthresholds may be used, e.g., in a range of 15 to 25. The beams havingsignal strength metrics that exceed the predetermined thresholds areconsidered the best beams and are selected to be used for positioningand to be used during the tracking mode. The number M of beams selectedmay be based on the type of positioning measurement being performed. Forexample, a timing based measurement may use multiple beams, e.g., 3beams, while an angle based measurement may use a single beam, e.g., thebeam presumably closest so the line of sight.

If in block 908, it is determined that the predetermined number M ofbeams have signal strength metrics that meet the requisite threshold(s),then the process flows to block 910 and the PRS from the selected beamsare processed for positioning, before returning to block 902.

In block 908, however, it may be determined that fewer than (or morethan) the predetermined number M of beams have signal strength metricsthat meet the requisite threshold(s), and the fraction of the full setof resources used in the acquisition mode to process the PRS may beincreased (or decreased) accordingly. For example, if in block 908 it isdetermined that less than the predetermined number M of beams may beselected, e.g., fewer than the predetermined number of beams have signalstrength metrics that exceed the predetermined threshold(s), the processflows to block 912 and the fraction of the full set of resources for thePRS is increased, e.g., doubled or otherwise increased, and theacquisition mode is repeated. For example, in the next positioningoccasion the increased set of resources is used to process the PRS fromeach beam and one or more signal strength metrics are determined (906)and compared to corresponding thresholds. The process is repeated untilthe predetermined number M of beams have signal strength metrics thatmeet the requisite threshold(s) or the full set of resources were used,and thus, a further increase in resources used to process the PRS is notpossible.

Alternatively, if in block 908 it is determined that more than thepredetermined number of beams have signal strength metrics that meet therequisite threshold(s), then only the predetermined number M of beamsare selected (e.g., the first M beams having signal strength metricsthat meet the requisite threshold(s)) and the process flows to block910. The next time the UE 104 is in acquisition mode 901, which may beafter a predetermined number of positioning occasions or an indicationthat the initial selection of beams is no longer valid, or in someimplementations, in the next positioning occasion, the fraction of thefull set of resources for the PRS may be decreased (e.g., halved) andthe acquisition mode 901 repeated until only the predetermined number Mof beams have signal strength metrics that meet the requisitethreshold(s).

Once the predetermined number M of beams have been selected during theacquisition mode, at the next positioning occasion, the process 900 goesinto tracking mode 903 via block 902. In tracking mode 903, the UE 104receives and processes the PRS from the selected beams using the fullset of resources for the PRS produced by each selected beam. Forexample, at block 920 in the tracking mode, the UE 104 selects the bestM beams for tracking, as determined in the acquisition mode 901. Atblock 922, the PRS from the selected beams are received and processedfor positioning using the full set of resources for the PRS in eachselected beam. Thus, the receiver may be tuned to receive the fullbandwidth of the PRS while in tracking mode and the processors may beconfigured to receive and integrate over the full number of repetitionsof the PRS while in tracking mode.

The UE 104 may return to the acquisition mode 901 after a predeterminednumber of positioning occasions in tracking mode 903. The UE 104 mayalso or alternatively return to the acquisition mode if a difference inthe signal strength metrics for the selected beams over multiplepositioning occasions indicates that the selection of beams from theinitial acquisition mode 901 is no longer valid, e.g., the UE 104 hassignificantly moved and/or conditions have changed. For example, at eachpositioning occasion, one or more signal strength metrics, e.g., SNR,RSRP, RSRQ, etc., for the selected beams may be compared to measuredsignal strength metrics from one or more preceding positioningoccasions, e.g., the measured signal strength metrics from theimmediately preceding positioning occasion, the measured signal strengthmetrics from the first positioning occasion used in tracking mode 903,or an average (or other (statistical combination) of the measured signalstrength metrics from a plurality of positioning occasions used intracking mode 903. If the difference between the signal strength metricsexceeds a predetermined threshold, the UE 104 may have moved orconditions may have changed and the initially selected beams may nolonger be the best beams. Accordingly, the process 900 may then returnto the acquisition mode 901 at block 902.

FIGS. 11A and 11B, by way of example, are graphs 1100 and 1150 thatillustrate 8 transmission beams B1, B2, B3, B4, B5, B6, B7, and B8produced by a base station in FR1. Similar to FIG. 8 , each beamincludes PRS provided over multiple positioning occasions, e.g., at 0,160, 320, 480, 640, and 800 ms. Each PRS occasion includes 1 subframe(N_(PRS)=1) of PRS and two repetitions, illustrated as two bars in eachpositioning occasion. The PRS may use the two symbols with Comb-2 optionand may have 272 resource blocks (RBs), and may require 4 k, 8 k, or 16k operations, depending on the performance requirements. Unlike FIG. 8 ,in FIGS. 11A and 11B, the UE 104 operates in an acquisition mode (block901 of FIG. 9 ) during the first positioning occasion, e.g., at Oms,during which the UE 104 receives and processes the PRS for each beamusing less than the full set of resources, and operates in a trackingmode (block 903 of FIG. 9 ) during the remaining positioning occasions,e.g., 160, 320, 480, 640, and 800 ms, during which the UE 104 receivesand processes the PRS for each beam using the full set of resources. Twosets of acquisition and tracking are illustrated in FIGS. 11A and 11B.

In FIG. 11A the UE 104 operates in acquisition mode (block 901 of FIG. 9) by receiving and processing the PRS for each beam using half of thefull bandwidth of the PRS for each beam, which is illustrated by therelatively shorter bars in the positioning occasion at Oms. By way ofexample, beams B1, B5, and B6 may be selected as the best beams forpositioning measurements during the acquisition mode in the firstpositioning occasion, e.g., based on one or more signal strength metricsthat meet the requisite threshold(s). In the tracking mode (block 903 ofFIG. 9 ) in subsequent positioning occasions, e.g., at 160, 320, 480,640, and 800 ms, the PRS from beams B1, B5, and B6 are received andprocessed using the full set of resources, e.g., the full bandwidth ofthe PRS for each beam, as illustrated by the relatively longer bars, forthe positioning measurements.

FIG. 11B the UE 104 operates in acquisition mode (block 901 of FIG. 9 )by receiving and processing the PRS for each beam using 1 repetition ofthe PRS for each beam at Oms, which is illustrated by the presence ofonly 1 bar in the positioning occasion at Oms. By way of example, beamsB1, B5, and B6 may be selected as the best beams for positioningmeasurements during the acquisition mode during the first positioningoccasion, e.g., based on one or more signal strength metrics that meetthe requisite threshold(s). In the tracking mode (block 903 of FIG. 9 )in subsequent positioning occasions, e.g., at 160, 320, 480, 640, and800 ms, the PRS from beams B1, B5, and B6 are received and processedusing the full set of resources, e.g., the full number of repetitions ofthe PRS for each beam, as illustrated by the presence of two bars, forthe positioning measurements.

FIGS. 11A and 11B illustrate a second set of acquisition and trackingmodes, where the first positioning occasion (e.g., Oms) uses less thanthe full set of resources during acquisition mode and the remainingpositioning occasions use the full set of resources during trackingmode. By way of example, the UE 104 may return to acquisition mode(block 901 of FIG. 9 ), after a predetermined number of positioningoccasions or if the signal strength metrics for one or more of the beamsB1, B5, and B6 in the positioning occasion at 800 ms changes by morethan a predetermined threshold, e.g., relative to one or more precedingpositioning occasions during the tracking mode. After the secondacquisition mode, FIGS. 11A and 11B illustrate that beams B2, B5 and B7are selected for positioning measurements, e.g., based on one or moresignal strength metrics that meet the requisite threshold(s).

FIG. 12 , by way of example, is a graph 1200 that illustrates 8transmission beams B1, B2, B3, B4, B5, B6, B7, and B8 produced by a basestation in FR1. Similar to FIG. 11A, each beam includes PRS providedover multiple positioning occasions, e.g., at 0, 160, 320, 480, 640, and800 ms. Each PRS occasion includes 1 subframe (N_(PRS)=1) of PRS and tworepetitions, illustrated as two bars in each positioning occasion. ThePRS may use the two symbols with Comb-2 option and may have 272 resourceblocks (RBs), and require 4 k, 8 k, or 16 k operations, depending on theperformance requirements. Two sets of acquisition and tracking areillustrated in FIG. 12 .

In FIG. 12 , the UE 104 operates in acquisition mode (block 901 of FIG.9) by receiving and processing the PRS for each beam using a quarter ofthe full bandwidth of the PRS for each beam, which is illustrated by therelatively shorter bars in the positioning occasion at Oms. In thisexample, fewer than the predetermined number of beams (3) have signalstrength metrics that exceed the predetermined thresholds (block 908 ofFIG. 9 ), illustrated with the dashed boxes around beams B1 and B4.Accordingly, the fraction of the full set of resources for the PRS isincreased, e.g., doubled, in the next positioning occasion (block 912 ofFIG. 9 ). In the second positioning occasion at 160 ms, the acquisitionmode is repeated using half of the full bandwidth of the PRS for eachbeam. With half of the full bandwidth of the PRS for each beam used thepredetermined number (3) of beams have signal strength metrics thatexceed the predetermined thresholds, as illustrated with the dashedboxes for beams B1, B4, and B6 during the second positioning occasion at160 ms. Accordingly, the UE 104 may select the beams B1, B4, and B6 forthe positioning measurements. During the tracking mode (block 903 ofFIG. 9 ) in the subsequent positioning occasions, e.g., at 320, 480,640, and 800 ms, the PRS from beams B1, B4, and B6 are received andprocessed using the full set of resources, e.g., the full bandwidth ofthe PRS for each beam, for the positioning measurements. In animplementation where a reduced number of repetitions is used duringacquisition mode (e.g., as illustrated in FIG. 11B), if fewer than thepredetermined number of beams (3) have signal strength metrics thatexceed the predetermined thresholds the number of repetitions may beincreased, e.g., doubled, increased incrementally, or otherwiseincreased, in the next positioning occasion (block 912 of FIG. 9 ).

In a subsequent set of acquisition and tracking, e.g., after apredetermined number of positioning occasions during the tracking modeor an indication that the UE 104 has moved or conditions have changed,the UE 104 may use the set of resources that successfully identified thepredetermined number (3) beams, i.e., half of the full bandwidth of thePRS for each beam.

FIG. 13 , by way of example, is a graph 1300 that illustrates 8transmission beams B1, B2, B3, B4, B5, B6, B7, and B8 produced by a basestation in FR1. Similar to FIG. 11A, each beam includes PRS providedover multiple positioning occasions, e.g., at 0, 160, 320, 480, 640, and800 ms. Each PRS occasion includes 1 subframe (N_(PRS)=1) of PRS and tworepetitions, illustrated as two bars in each positioning occasion. ThePRS may use the two symbols with Comb-2 option and may have 272 resourceblocks (RBs), and require 4 k, 8 k, or 16 k operations, depending on theperformance requirements. Two sets of acquisition and tracking areillustrated in FIG. 13 .

In FIG. 13 , the UE 104 operates in acquisition mode (block 901 of FIG.9 ) by receiving and processing the PRS for each beam using half of thefull bandwidth of the PRS for each beam. In this example, more than thepredetermined number of beams (3) have signal strength metrics thatexceed the predetermined thresholds (block 908 of FIG. 9 ), illustratedwith the dashed boxes on beams B1, B4, B5, and B6. Accordingly, apredetermined number of beams (e.g., the first M beams), illustrated asbeams B1, B2, and B5, may be selected as the best beams for thepositioning measurements and are used in the tracking mode inpositioning occasions 160, 320, 480, 640, 800 ms.

In the next acquisition mode, e.g., as illustrated at Oms in the secondset of positioning occasions, the UE 104 decreases the resources used toreceive and process the PRS for each beam, e.g., as illustrated as usinga quarter of the full bandwidth of the PRS for each beam. In thisexample, using reduced resources in the second acquisition mode, thepredetermined number of beams (3) have signal strength metrics thatexceed the predetermined thresholds (block 908 of FIG. 9 ), illustratedwith the dashed boxes on beams B1, B4, and B6. The selected beams maythen be used for the positioning measurements and the tracking mode inpositioning occasions 160, 320, 480, 640, 800 ms.

FIGS. 14A and 14B illustrate graphs 1400 and 1450 showing the savings inmultiplier—accumulator (MAC) operations for a cell transmitting 8 beamsin FR1, and a cell transmitting 64 beams in FR2, respectively. Asillustrated in FIG. 14A, as illustrated with bars 1402, the total MACsused to acquire PRS for RSTD over 272 RB (e.g., the full set ofresources over all 8 beams) vs MACs used to acquire PRS for RSTD over272 RB (e.g., the full set of resources over 3 beams) drops from 630,272to 241,472. As illustrated with bars 1404, the total MACs used toacquire PRS for RSTD over 136 RB (e.g., half of the resources over all 8beams) vs MACs used to acquire PRS for RSTD over 272 RB (e.g., the fullset of resources over 3 beams) drops from 298,752 to 241,472. Asillustrated with bars 1406, the total MACs used to acquire PRS for RSTDover 68 RB (e.g., a quarter of the resources over all 8 beams) vs MACsused to acquire PRS for RSTD over 272 RB (e.g., the full set ofresources over 3 beams) increases from 141,184 to 241,472. Theprocessing savings (power savings) for the acquisition mode areillustrated in Table 2.

TABLE 2 272 RB 136 RB 68 RB MAC Operations 630,272 298,752 141,184Percent Savings 100% 47.4% 22.4%

As illustrated in FIG. 14A, as illustrated with bars 1452, the totalMACs used to acquire PRS for RSTD over 264 RB (e.g., the full set ofresources over all 64 beams) vs MACs used to acquire PRS for RSTD over264 RB (e.g., the full set of resources over 3 beams) drops from4,954,112 to 708,032. As illustrated with bars 1454, the total MACs usedto acquire PRS for RSTD over 132 RB (e.g., half of the resources overall 64 beams) vs MACs used to acquire PRS for RSTD over 264 RB (e.g.,the full set of resources over 3 beams) drops from 2,345,984 to 708,032.As illustrated with bars 1456, the total MACs used to acquire PRS forRSTD over 68 RB (e.g., a quarter of the resources over all 64 beams) vsMACs used to acquire PRS for RSTD over 264 RB (e.g., the full set ofresources over 3 beams) decreases from 1,115,136 to 708,032. Theprocessing savings (power savings) for the acquisition mode areillustrated in Table 3.

TABLE 3 264 RB 132 RB 68 RB MAC Operations 4,954,112 2,345,984 1,115,136Percent Savings 100% 47.3% 22.5%

Thus, as can be seen in FIGS. 14A and 14B and Tables 2 and 3, the UE 104may receive a significant processing/power savings in acquisition modeusing less than all of the resources for the PRS and the gains are morepronounced using smaller fractions of the full set of resources.

FIG. 15 shows a schematic block diagram illustrating certain exemplaryfeatures of a UE 1500, e.g., which may be UE 104 shown in FIG. 1 ,enabled to support positioning using an acquisition mode in which lessthan the full set of resources are used for PRS processing for all beamsand a tracking mode in which the full set of resources are used forselected beams, as described herein. The UE 1500 may perform the processflow shown in FIGS. 9 and 16 and algorithms described herein. UE 1500may, for example, include one or more processors 1502, memory 1504, anexternal interface such as a transceiver 1510 (e.g., wireless networkinterface), which may be operatively coupled with one or moreconnections 1506 (e.g., buses, lines, fibers, links, etc.) tonon-transitory computer readable medium 1520 and memory 1504. The UE1500 may further include additional items, which are not shown, such asa user interface that may include e.g., a display, a keypad or otherinput device, such as virtual keypad on the display, through which auser may interface with the UE, or a satellite positioning systemreceiver. In certain example implementations, all or part of UE 1500 maytake the form of a chipset, and/or the like. Transceiver 1510 may, forexample, include a transmitter 1512 enabled to transmit one or moresignals over one or more types of wireless communication networks and areceiver 1514 to receive one or more signals transmitted over the one ormore types of wireless communication networks.

In some embodiments, UE 1500 may include antenna 1511, which may beinternal or external. UE antenna 1511 may be used to transmit and/orreceive signals processed by transceiver 1510. In some embodiments, UEantenna 1511 may be coupled to transceiver 1510. The antenna 1511 mayinclude more than one antenna element, and may be capable of dualpolarization, MIMO-capable, beam forming, beam steering, and beamtracking. In some implementations, the antenna 1511 may include aplurality of panels, and each panel may include a multiple antenna arrayelements. In some embodiments, measurements of signals received(transmitted) by UE 1500 may be performed at the point of connection ofthe UE antenna 1511 and transceiver 1510. For example, the measurementpoint of reference for received (transmitted) RF signal measurements maybe an input (output) terminal of the receiver 1514 (transmitter 1512)and an output (input) terminal of the UE antenna 1511. In a UE 1500 withmultiple UE antennas 1511 or antenna arrays, the antenna connector maybe viewed as a virtual point representing the aggregate output (input)of multiple UE antennas. In some embodiments, UE 1500 may measurereceived signals including signal strength metrics, e.g., SNR, RSRP,RSRQ, and positioning measurements may be processed by the one or moreprocessors 1502. For example, the UE 104 may measure the signal strengthmetrics of each transmitted beam to determine the best beam(s) receivedby the UE 104. For example, transmitted beams with signal strengthmetrics that are above predetermined thresholds may be treated as thebest beam(s). The number of beams selected as the best beams may bebased on the type of positioning measurements to be performed, e.g.,time based measurements or angle based measurements.

The one or more processors 1502 may be implemented using a combinationof hardware, firmware, and software. For example, the one or moreprocessors 1502 may be configured to perform the functions discussedherein by implementing one or more instructions or program code 1508 ona non-transitory computer readable medium, such as medium 1520 and/ormemory 1504. In some embodiments, the one or more processors 1502 mayrepresent one or more circuits configurable to perform at least aportion of a data signal computing procedure or process related to theoperation of UE 1500.

The medium 1520 and/or memory 1504 may store instructions or programcode 1508 that contain executable code or software instructions thatwhen executed by the one or more processors 1502 cause the one or moreprocessors 1502 to operate as a special purpose computer programmed toperform the techniques disclosed herein. As illustrated in UE 1500, themedium 1520 and/or memory 1504 may include one or more components ormodules that may be implemented by the one or more processors 1502 toperform the methodologies described herein. While the components ormodules are illustrated as software in medium 1520 that is executable bythe one or more processors 1502, it should be understood that thecomponents or modules may be stored in memory 1504 or may be dedicatedhardware either in the one or more processors 1502 or off theprocessors. A number of software modules and data tables may reside inthe medium 1520 and/or memory 1504 and be utilized by the one or moreprocessors 1502 in order to manage both communications and thefunctionality described herein. It should be appreciated that theorganization of the contents of the medium 1520 and/or memory 1504 asshown in UE 1500 is merely exemplary, and as such the functionality ofthe modules and/or data structures may be combined, separated, and/or bestructured in different ways depending upon the implementation of the UE1500.

The medium 1520 and/or memory 1504 may include a positioning sessionmodule 1522 that when implemented by the one or more processors 1502configures the one or more processors 1502 to engage in a positioningsession with a location server through a serving base station, via thewireless transceiver 1510, including receiving a request for capabilityinformation and sending a response for capability information, receivingassistance data, receiving a request to provide location information,performing positioning measurements by receiving and measuring DLreference signals, transmitting UL references signals, estimating aposition, sending a provide location information response, which mayinclude positioning measurements and/or a position estimate.

The medium 1520 and/or memory 1504 may include a resource module 1524that when implemented by the one or more processors 1502 configures theone or more processors 1502 to select resources to be used for receivingand processing PRS. For example, during acquisition mode, the one ormore processors 1502 may be configured to initialize the set ofresources that will be used for processing the PRS for each beam basedon a fraction of the full set of resources available. For example, theone or more processors 1502 may be configured to tune the receiver 1514to receive a fraction of the full bandwidth of the PRS while inacquisition mode, and to tune the receiver 1514 to the full bandwidth ofthe PRS while in tracking mode. In another example, during acquisitionmode, the one or more processors 1502 may be configured to initializethe set of resources that will be used for processing the PRS for eachbeam based on a fraction or reduced number of repetitions of the PRS.For example, the one or more processors 1502 may be configured toreceive and integrate over less than the full number of repetitions ofthe PRS while in acquisition mode, and to receive and integrate over thefull number of repetitions of the PRS while in tracking mode. The one ormore processors 1502 may be configured to increase or decrease thefraction of the full set of resources used to process PRS in subsequentpositioning occasions, e.g., if less than or more than a predeterminednumber of beams have signal strength metrics that meet a requisitethreshold. During tracking mode, the one or more processors 1502 may beconfigured to use the full set of resources for the PRS for selectedbeams.

The medium 1520 and/or memory 1504 may include a signal strength module1526 that when implemented by the one or more processors 1502 configuresthe one or more processors 1502 to determine a signal strength metricfor the PRS received in each beam, e.g., during acquisition mode ortracking mode. The signal strength metrics, for example, may be SNR,RSRP, RSRQ, or other types of measurements. While in acquisition mode,the one or more processors 1502 may be configured to compare the signalstrength metrics to predetermined thresholds to determine if the PRSreceived from each beam exceeds the threshold. In tracking mode, the oneor more processors 1502 may be configured to compare the signal strengthmetrics to signal strength metrics generated in one or more previouspositioning occasions, e.g., the immediately preceding positioningoccasion, the first positioning occasion of the tracking mode, or anaverage or combination of signal strength metrics from a plurality ofproceeding positioning occasions.

The medium 1520 and/or memory 1504 may include a beam selection module1528 that when implemented by the one or more processors 1502 configuresthe one or more processors 1502 to select a predetermined number of bestbeams for PRS based on the comparison of the signal strength metrics tothe corresponding thresholds during the acquisition mode. Thepredetermined number of beams may be based on the type of positioningmeasurement being performed, e.g., timing based, which may use multiplebeams, or angle based, which may use a single beam. The one or moreprocessors 1502 may be configured to determined when fewer or a greaternumber than the predetermined number of beams may be selected, which mayprompt an increase or decrease in the resources used to process the PRS.The one or more processors 1502 may be further configured to determinewhen the selection of beams from a previous acquisition mode may nolonger be valid, e.g., after operating in tracking mode for apredetermined number of positioning occasions or when the differencebetween the signal strength metrics between positioning occasions in thetracking mode is greater than a threshold, and prompting a return to theacquisition mode.

The medium 1520 and/or memory 1504 may include a tracking module 1530that when implemented by the one or more processors 1502 configures theone or more processors 1502 to operate in tracking mode in which PRSfrom a selected number of beams are processed using the full resourcesfor the PRS and positioning measurements are performed.

The methodologies described herein may be implemented by various meansdepending upon the application. For example, these methodologies may beimplemented in hardware, firmware, software, or any combination thereof.For a hardware implementation, the one or more processors 1502 may beimplemented within one or more application specific integrated circuits(ASICs), digital signal processors (DSPs), digital signal processingdevices (DSPDs), programmable logic devices (PLDs), field programmablegate arrays (FPGAs), processors, controllers, micro-controllers,microprocessors, electronic devices, other electronic units designed toperform the functions described herein, or a combination thereof.

For a firmware and/or software implementation, the methodologies may beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. Any machine readable mediumtangibly embodying instructions may be used in implementing themethodologies described herein. For example, software codes may bestored in a non-transitory computer readable medium 1520 or memory 1504that is connected to and executed by the one or more processors 1502.Memory may be implemented within the one or more processors or externalto the one or more processors. As used herein the term “memory” refersto any type of long term, short term, volatile, nonvolatile, or othermemory and is not to be limited to any particular type of memory ornumber of memories, or type of media upon which memory is stored.

If implemented in firmware and/or software, the functions may be storedas one or more instructions or program code 1508 on a non-transitorycomputer readable medium, such as medium 1520 and/or memory 1504.Examples include computer readable media encoded with a data structureand computer readable media encoded with a computer program 1508. Forexample, the non-transitory computer readable medium including programcode 1508 stored thereon may include program code 1508 to supportpositioning using array gain distribution variation as a function ofangle and frequency in a manner consistent with disclosed embodiments.Non-transitory computer readable medium 1520 includes physical computerstorage media. A storage medium may be any available medium that can beaccessed by a computer. By way of example, and not limitation, suchnon-transitory computer readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to storedesired program code 1508 in the form of instructions or data structuresand that can be accessed by a computer; disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer readable media.

In addition to storage on computer readable medium 1520, instructionsand/or data may be provided as signals on transmission media included ina communication apparatus. For example, a communication apparatus mayinclude a transceiver 1510 having signals indicative of instructions anddata. The instructions and data are configured to cause one or moreprocessors to implement the functions outlined in the claims. That is,the communication apparatus includes transmission media with signalsindicative of information to perform disclosed functions.

Memory 1504 may represent any data storage mechanism. Memory 1504 mayinclude, for example, a primary memory and/or a secondary memory.Primary memory may include, for example, a random access memory, readonly memory, etc. While illustrated in this example as being separatefrom one or more processors 1502, it should be understood that all orpart of a primary memory may be provided within or otherwiseco-located/coupled with the one or more processors 1502. Secondarymemory may include, for example, the same or similar type of memory asprimary memory and/or one or more data storage devices or systems, suchas, for example, a disk drive, an optical disc drive, a tape drive, asolid state memory drive, etc.

In certain implementations, secondary memory may be operativelyreceptive of, or otherwise configurable to couple to a non-transitorycomputer readable medium 1520. As such, in certain exampleimplementations, the methods and/or apparatuses presented herein maytake the form in whole or part of a computer readable medium 1520 thatmay include computer implementable code 1508 stored thereon, which ifexecuted by one or more processors 1502 may be operatively enabled toperform all or portions of the example operations as described herein.Computer readable medium 1520 may be a part of memory 1504.

FIG. 16 shows a flowchart for an exemplary method 1600 for supportingpositioning of a mobile device in a wireless network performed by themobile device, such as UE 104, in a manner consistent with disclosedimplementation.

At block 1602, the mobile device receives positioning reference signals(PRS) transmitted in a plurality of beams from a base station using lessthan a full set of resources for the PRS produced by each beam, whereinless than the full set of resources for the PRS comprises less than afull bandwidth, less than a full number of repetitions in a positioningoccasion, or a combination thereof, e.g., as discussed at blocks 904 and906 of FIG. 9 and FIGS. 11A, 11B, 12, and 13 . A means for receivingpositioning reference signals (PRS) transmitted in a plurality of beamsfrom a base station using less than a full set of resources for the PRSproduced by each beam, wherein less than the full set of resources forthe PRS comprises less than a full bandwidth, less than a full number ofrepetitions in a positioning occasion, or a combination thereof mayinclude, e.g., the wireless transceiver 1510 and one or more processors1502 with dedicated hardware or implementing executable code or softwareinstructions in memory 1504 and/or medium 1520 such as the positioningsession module 1522, and the resource module 1524 in UE 1500 shown inFIG. 15 .

At block 1604, the mobile device selects a predetermined number of beamsfrom the plurality of beams, e.g., as discussed at blocks 906 and 908 ofFIG. 9 and FIGS. 11A, 11B, 12, and 13 . A means for selecting apredetermined number of beams from the plurality of beams may include,e.g., the one or more processors 1502 with dedicated hardware orimplementing executable code or software instructions in memory 1504and/or medium 1520 such as the signal strength module 1526, and the beamselection module 1528 in UE 1500 shown in FIG. 15 .

At block 1606, the mobile device receives the PRS from the selectedbeams using the full set of resources for the PRS produced by eachselected beam, e.g., as discussed at blocks 920 and 922 of FIG. 9 andFIGS. 11A, 11B, 12, and 13 . A means for receiving the PRS from theselected beams using the full set of resources for the PRS produced byeach selected beam may include, e.g., the wireless transceiver 1510 andone or more processors 1502 with dedicated hardware or implementingexecutable code or software instructions in memory 1504 and/or medium1520 such as the positioning session module 1522, the resource module1524, and the receiving module 1530 in UE 1500 shown in FIG. 15 .

In one implementation, the mobile device may perform positioning of themobile device using the received PRS from the selected beams, e.g., asdiscussed at block 922 of FIG. 9 and FIGS. 11A, 11B, 12, and 13 . Ameans for performing positioning of the mobile device using the receivedPRS from the selected beams may include, e.g., the wireless transceiver1510 and one or more processors 1502 with dedicated hardware orimplementing executable code or software instructions in memory 1504and/or medium 1520 such as the positioning session module 1522 and thereceiving module 1530 in UE 1500 shown in FIG. 15 .

In one implementation, the mobile device may receive the PRS using lessthan the full set of resources for the PRS produced by each beam byselecting a fraction of the full bandwidth and tuning to receive radiosignals on the fraction of the full bandwidth, and may receive the PRSfrom the selected beams using the full set of resources for the PRSproduced by each selected beam by tuning to receive radio signals on thefull bandwidth, e.g., as discussed at blocks 904 and 906 of FIG. 9 .

In one implementation, the mobile device may receive the PRS using lessthan the full set of resources for the PRS produced by each beam byselecting a fraction of the full number of repetitions for the PRS andintegrating over only the fraction of the full number of repetitions toreceive the PRS, and may receive the PRS from the selected beams usingthe full set of resources for the PRS produced by each selected beam byintegrating over the full number of repetitions to receive the PRS,e.g., as discussed at blocks 904 and 906 of FIG. 9 .

In one implementation, the mobile device may select the predeterminednumber of beams by determining at least one signal strength metric foreach beam in the plurality of beams, e.g., as discussed at block 906 ofFIG. 9 . The mobile device may compare the at least one signal strengthmetric to a corresponding at least one predetermined threshold, e.g., asdiscussed at block 908 of FIG. 9 . The mobile device may select thepredetermined number of beams based on the comparison of the at leastone signal strength metric to the corresponding at least onepredetermined threshold, e.g., as discussed at blocks 908 and 910 ofFIG. 9 . For example, the at least one signal strength metric comprisesSignal to Noise Ratio (SNR), Reference Signal Received Power (RSRP), orReference Signal Received Quality (RSRQ). A means for selecting thepredetermined number of beams by determining at least one signalstrength metric for each beam in the plurality of beams, a means forcomparing the at least one signal strength metric to a corresponding atleast one predetermined threshold, and a means for selecting thepredetermined number of beams based on the comparison of the at leastone signal strength metric to the corresponding at least onepredetermined threshold may include, e.g., the one or more processors1502 with dedicated hardware or implementing executable code or softwareinstructions in memory 1504 and/or medium 1520 such as the signalstrength module 1526, and the beam selection module 1528 in UE 1500shown in FIG. 15 .

In one implementation, the mobile device may select the predeterminednumber of beams based on at least one signal strength metric of eachbeam by selecting at least one of a fraction of the full bandwidth or afraction of the full number of repetitions to receive the PRS, e.g., asdiscussed at block 904 of FIG. 9 . The mobile device may determinewhether the at least one signal strength metric exceeds a correspondingat least one predetermined threshold, e.g., as discussed at blocks 906and 908 of FIG. 9 . The mobile device may increase the at least one ofthe fraction of the full bandwidth or the fraction of the full number ofrepetitions to receive the PRS when the at least one signal strengthmetric does not exceed the corresponding at least one predeterminedthreshold for the predetermined number of beams, e.g., as discussed atblock 912 of FIG. 9 . For example, the mobile device may iterativelyincrease the at least one of the fraction of the full bandwidth or thefraction of the full number of repetitions to receive the PRS anddetermining whether the at least one signal strength metric exceeds thecorresponding at least one predetermined threshold until the at leastone signal strength metric exceeds the corresponding at least onepredetermined threshold for the predetermined number of beams. A meansfor selecting at least one of a fraction of the full bandwidth or afraction of the full number of repetitions to receive the PRS, a meansfor determining whether the at least one signal strength metric exceedsa corresponding at least one predetermined threshold, and a means forincreasing the at least one of the fraction of the full bandwidth or thefraction of the full number of repetitions to receive the PRS when theat least one signal strength metric does not exceed the corresponding atleast one predetermined threshold for the predetermined number of beamsmay include, e.g., the wireless transceiver 1510 and one or moreprocessors 1502 with dedicated hardware or implementing executable codeor software instructions in memory 1504 and/or medium 1520 such as thesignal strength module 1526, and the beam selection module 1528 and theresource module 1524 in UE 1500 shown in FIG. 15 .

In one implementation, the mobile device may select the predeterminednumber of beams based on at least one signal strength metric of eachbeam by selecting at least one of a fraction of the full bandwidth or afraction of the full number of repetitions to receive the PRS, e.g., asdiscussed at block 904 of FIG. 9 . The mobile device may determinewhether the at least one signal strength metric exceeds a correspondingat least one predetermined threshold, e.g., as discussed at blocks 906and 908 of FIG. 9 . The mobile device may select the predeterminednumber of beams for receiving when the at least one signal strengthmetric exceeds the corresponding at least one predetermined thresholdfor more than the predetermined number of beams, e.g., as discussed atblock 908 and 910 of FIG. 9 . The mobile device may decrease the atleast one of the fraction of the full bandwidth or the fraction of thefull number of repetitions to receive the PRS in a subsequentpositioning occasion. A means for selecting at least one of a fractionof the full bandwidth or a fraction of the full number of repetitions toreceive the PRS, a means for determining whether the at least one signalstrength metric exceeds a corresponding at least one predeterminedthreshold, and a means for selecting the predetermined number of beamsfor receiving when the at least one signal strength metric exceeds thecorresponding at least one predetermined threshold for more than thepredetermined number of beams may include, e.g., the wirelesstransceiver 1510 and one or more processors 1502 with dedicated hardwareor implementing executable code or software instructions in memory 1504and/or medium 1520 such as the signal strength module 1526, and the beamselection module 1528 and the resource module 1524 in UE 1500 shown inFIG. 15 .

In one embodiment, the mobile device may receive the PRS from theselected beams using the full set of resources for the PRS produce byeach selected beam for multiple positioning occasions, e.g., asdiscussed at blocks 920 and 922 of FIG. 9 and FIGS. 11A, 11B, 12, and 13. The mobile device may determine a difference in at least one signalstrength metric between two positioning occasions for one or moreselected beams is below a predetermined threshold, e.g., as discussed atblock 922 of FIG. 9 . The mobile device may receive the PRS transmittedin the plurality of beams using less than the full set of resources forthe PRS produced by each beam after determining the difference is belowthe predetermined threshold, e.g., as discussed at blocks 922 and 902 ofFIG. 9 and FIGS. 11A, 11B, 12, and 13 . A means for receiving the PRSfrom the selected beams using the full set of resources for the PRSproduce by each selected beam for multiple positioning occasions mayinclude, e.g., the wireless transceiver 1510 and one or more processors1502 with dedicated hardware or implementing executable code or softwareinstructions in memory 1504 and/or medium 1520 such as the positioningsession module 1522, the resource module 1524, and the receiving module1530 in UE 1500 shown in FIG. 15 . A means for determining a differencein at least one signal strength metric between two positioning occasionsfor one or more selected beams is below a predetermined threshold mayinclude, e.g., the one or more processors 1502 with dedicated hardwareor implementing executable code or software instructions in memory 1504and/or medium 1520 such as the positioning session module 1522, thesignal strength module 1526, and the beam selection module 1528 in UE1500 shown in FIG. 15 . A means for receiving the PRS transmitted in theplurality of beams using less than the full set of resources for the PRSproduced by each beam after determining the difference is below thepredetermined threshold may include, e.g., the wireless transceiver 1510and one or more processors 1502 with dedicated hardware or implementingexecutable code or software instructions in memory 1504 and/or medium1520 such as the positioning session module 1522, the resource module1524, and the beam selection module 1528 in UE 1500 shown in FIG.

In one embodiment, the mobile device may receive the PRS from theselected beams using the full set of resources for the PRS produce byeach selected beam for multiple positioning occasions, e.g., asdiscussed at blocks 920 and 922 of FIG. 9 and FIGS. 11A, 11B, 12, and 13. The mobile device may receive the PRS transmitted in the plurality ofbeams using less than the full set of resources for the PRS produced byeach beam after the predetermined number of positioning occasions, e.g.,as discussed at blocks 922 and 902 of FIG. 9 and FIGS. 11A, 11B, 12, and13 . A means for receiving the PRS from the selected beams using thefull set of resources for the PRS produce by each selected beam for apredetermined number of positioning occasions may include, e.g., thewireless transceiver 1510 and one or more processors 1502 with dedicatedhardware or implementing executable code or software instructions inmemory 1504 and/or medium 1520 such as the positioning session module1522, the resource module 1524, and the receiving module 1530 in UE 1500shown in FIG. 15 . A means for receiving the PRS transmitted in theplurality of beams using less than the full set of resources for the PRSproduced by each beam after the predetermined number of positioningoccasions may include, e.g., the wireless transceiver 1510 and one ormore processors 1502 with dedicated hardware or implementing executablecode or software instructions in memory 1504 and/or medium 1520 such asthe positioning session module 1522, the resource module 1524, and thebeam selection module 1526 in UE 1500 shown in FIG. 15 .

Reference throughout this specification to “one example”, “an example”,“certain examples”, or “exemplary implementation” means that aparticular feature, structure, or characteristic described in connectionwith the feature and/or example may be included in at least one featureand/or example of claimed subject matter. Thus, the appearances of thephrase “in one example”, “an example”, “in certain examples” or “incertain implementations” or other like phrases in various placesthroughout this specification are not necessarily all referring to thesame feature, example, and/or limitation. Furthermore, the particularfeatures, structures, or characteristics may be combined in one or moreexamples and/or features.

Some portions of the detailed description included herein are presentedin terms of algorithms or symbolic representations of operations onbinary digital signals stored within a memory of a specific apparatus orspecial purpose computing device or platform. In the context of thisparticular specification, the term specific apparatus or the likeincludes a general purpose computer once it is programmed to performparticular operations pursuant to instructions from program software.Algorithmic descriptions or symbolic representations are examples oftechniques used by those of ordinary skill in the signal processing orrelated arts to convey the substance of their work to others skilled inthe art. An algorithm is here, and generally, is considered to be aself-consistent sequence of operations or similar signal processingleading to a desired result. In this context, operations or processinginvolve physical manipulation of physical quantities. Typically,although not necessarily, such quantities may take the form ofelectrical or magnetic signals capable of being stored, transferred,combined, compared or otherwise manipulated. It has proven convenient attimes, principally for reasons of common usage, to refer to such signalsas bits, data, values, elements, symbols, characters, terms, numbers,numerals, or the like. It should be understood, however, that all ofthese or similar terms are to be associated with appropriate physicalquantities and are merely convenient labels. Unless specifically statedotherwise, as apparent from the discussion herein, it is appreciatedthat throughout this specification discussions utilizing terms such as“processing,” “computing,” “calculating,” “determining” or the likerefer to actions or processes of a specific apparatus, such as a specialpurpose computer, special purpose computing apparatus or a similarspecial purpose electronic computing device. In the context of thisspecification, therefore, a special purpose computer or a similarspecial purpose electronic computing device is capable of manipulatingor transforming signals, typically represented as physical electronic ormagnetic quantities within memories, registers, or other informationstorage devices, transmission devices, or display devices of the specialpurpose computer or similar special purpose electronic computing device.

In the preceding detailed description, numerous specific details havebeen set forth to provide a thorough understanding of claimed subjectmatter. However, it will be understood by those skilled in the art thatclaimed subject matter may be practiced without these specific details.In other instances, methods and apparatuses that would be known by oneof ordinary skill have not been described in detail so as not to obscureclaimed subject matter.

The terms, “and”, “or”, and “and/or” as used herein may include avariety of meanings that also are expected to depend at least in partupon the context in which such terms are used. Typically, “or” if usedto associate a list, such as A, B or C, is intended to mean A, B, and C,here used in the inclusive sense, as well as A, B or C, here used in theexclusive sense. In addition, the term “one or more” as used herein maybe used to describe any feature, structure, or characteristic in thesingular or may be used to describe a plurality or some othercombination of features, structures or characteristics. Though, itshould be noted that this is merely an illustrative example and claimedsubject matter is not limited to this example.

While there has been illustrated and described what are presentlyconsidered to be example features, it will be understood by thoseskilled in the art that various other modifications may be made, andequivalents may be substituted, without departing from claimed subjectmatter. Additionally, many modifications may be made to adapt aparticular situation to the teachings of claimed subject matter withoutdeparting from the central concept described herein.

Implementation examples are described in the following numbered clauses:

-   -   1. A method for supporting positioning of a mobile device in a        wireless network performed by the mobile device, the method        comprising:    -   receiving positioning reference signals (PRS) transmitted in a        plurality of beams from a base station using less than a full        set of resources for the PRS produced by each beam, wherein less        than the full set of resources for the PRS comprises less than a        full bandwidth, less than a full number of repetitions in a        positioning occasion, or a combination thereof;    -   selecting a predetermined number of beams from the plurality of        beams; and    -   receiving the PRS from the selected beams using the full set of        resources for the PRS produced by each selected beam.    -   2. The method of clause 1, further comprising performing        positioning of the mobile device using the received PRS from the        selected beams.    -   3. The method of either of clauses 1 or 2, wherein receiving the        PRS using less than the full set of resources for the PRS        produced by each beam comprises selecting a fraction of the full        bandwidth and tuning to receive radio signals on the fraction of        the full bandwidth, and wherein receiving the PRS from the        selected beams using the full set of resources for the PRS        produced by each selected beam comprises tuning to receive radio        signals on the full bandwidth.    -   4. The method of any of clauses 1-3, wherein receiving the PRS        using less than the full set of resources for the PRS produced        by each beam comprises selecting a fraction of the full number        of repetitions for the PRS and integrating over only the        fraction of the full number of repetitions to receive the PRS,        and wherein receiving the PRS from the selected beams using the        full set of resources for the PRS produced by each selected beam        comprises integrating over the full number of repetitions to        receive the PRS.    -   5. The method of any of clauses 1-4, wherein selecting the        predetermined number of beams comprises:    -   determining at least one signal strength metric for each beam in        the plurality of beams;    -   comparing the at least one signal strength metric to a        corresponding at least one predetermined threshold; and    -   selecting the predetermined number of beams based on the        comparison of the at least one signal strength metric to the        corresponding at least one predetermined threshold.    -   6. The method of clause 5, wherein the at least one signal        strength metric comprises Signal to Noise Ratio (SNR), Reference        Signal Received Power (RSRP), or Reference Signal Received        Quality (RSRQ).    -   7. The method of any of clauses 1-6, wherein the predetermined        number of beams are selected based on at least one signal        strength metric of each beam, and wherein the method further        comprises:    -   selecting at least one of a fraction of the full bandwidth or a        fraction of the full number of repetitions to receive the PRS;    -   determining whether the at least one signal strength metric        exceeds a corresponding at least one predetermined threshold;        and    -   increasing the at least one of the fraction of the full        bandwidth or the fraction of the full number of repetitions to        receive the PRS when the at least one signal strength metric        does not exceed the corresponding at least one predetermined        threshold for the predetermined number of beams.    -   8. The method of clause 7, further comprising iteratively        increasing the at least one of the fraction of the full        bandwidth or the fraction of the full number of repetitions to        receive the PRS and determining whether the at least one signal        strength metric exceeds the corresponding at least one        predetermined threshold until the at least one signal strength        metric exceeds the corresponding at least one predetermined        threshold for the predetermined number of beams.    -   9. The method of any of clauses 1-6, wherein the predetermined        number of beams are selected based on at least one signal        strength metric of each beam, and wherein the method further        comprises:    -   selecting at least one of a fraction of the full bandwidth or a        fraction of the full number of repetitions to receive the PRS;    -   determining whether the at least one signal strength metric        exceeds a corresponding at least one predetermined threshold;        and    -   selecting the predetermined number of beams for receiving when        the at least one signal strength metric exceeds the        corresponding at least one predetermined threshold for more than        the predetermined number of beams.    -   10. The method of clause 9, the method further comprising        decreasing the at least one of the fraction of the full        bandwidth or the fraction of the full number of repetitions to        receive the PRS in a subsequent positioning occasion.    -   11. The method of any of clauses 1-10, further comprising:    -   receiving the PRS from the selected beams using the full set of        resources for the PRS produce by each selected beam for multiple        positioning occasions;    -   determining a difference in at least one signal strength metric        between two positioning occasions for one or more selected beams        is below a predetermined threshold; and    -   receiving the PRS transmitted in the plurality of beams using        less than the full set of resources for the PRS produced by each        beam after determining the difference is below the predetermined        threshold.    -   12. The method of any of clauses 1-10, further comprising:    -   receiving the PRS from the selected beams using the full set of        resources for the PRS produce by each selected beam for a        predetermined number of positioning occasions; and    -   receiving the PRS transmitted in the plurality of beams using        less than the full set of resources for the PRS produced by each        beam after the predetermined number of positioning occasions.    -   13. A mobile device configured for supporting positioning of the        mobile device in a wireless network, comprising:    -   a wireless transceiver configured to wirelessly communicate in        the wireless network;    -   at least one memory;    -   at least one processor coupled to the wireless transceiver and        the at least one memory, wherein the at least one processor is        configured to:    -   receive, using the wireless transceiver, positioning reference        signals (PRS) transmitted in a plurality of beams from a base        station using less than a full set of resources for the PRS        produced by each beam, wherein less than the full set of        resources for the PRS comprises less than a full bandwidth, less        than a full number of repetitions in a positioning occasion, or        a combination thereof;    -   select a predetermined number of beams from the plurality of        beams; and    -   receive, using the wireless transceiver, the PRS from the        selected beams using the full set of resources for the PRS        produced by each selected beam.    -   14. The mobile device of clause 13, wherein the at least one        processor is further configured to perform positioning of the        mobile device using the received PRS from the selected beams.    -   15. The mobile device of any of clauses 13 or 14, wherein the at        least one processor is configured to receive the PRS using less        than the full set of resources for the PRS produced by each beam        by being configured to select a fraction of the full bandwidth        and tune the wireless transceiver to receive radio signals on        the fraction of the full bandwidth, and wherein the at least one        processor is configured to receive the PRS from the selected        beams using the full set of resources for the PRS produced by        each selected beam by being configured to tune the wireless        transceiver to receive radio signals on the full bandwidth.    -   16. The mobile device of any of clauses 13-15, wherein the at        least one processor is configured to receive the PRS using less        than the full set of resources for the PRS produced by each beam        by being configured to select a fraction of the full number of        repetitions for the PRS and integrate over only the fraction of        the full number of repetitions to receive the PRS, and wherein        the at least one processor is configured to receive the PRS from        the selected beams using the full set of resources for the PRS        produced by each selected beam by being configured to integrate        over the full number of repetitions to receive the PRS.    -   17. The mobile device of any of clauses 13-16, wherein the at        least one processor is configured to select the predetermined        number of beams by being configured to:    -   determine at least one signal strength metric for each beam in        the plurality of beams;    -   compare the at least one signal strength metric to a        corresponding at least one predetermined threshold; and    -   select the predetermined number of beams based on the comparison        of the at least one signal strength metric to the corresponding        at least one predetermined threshold.    -   18. The mobile device of clause 17, wherein the at least one        signal strength metric comprises Signal to Noise Ratio (SNR),        Reference Signal Received Power (RSRP), or Reference Signal        Received Quality (RSRQ).    -   19. The mobile device of any of clauses 13-18, wherein the        predetermined number of beams are selected based on at least one        signal strength metric of each beam, and wherein the at least        one processor is further configured to:    -   select at least one of a fraction of the full bandwidth or a        fraction of the full number of repetitions to receive the PRS;    -   determine whether the at least one signal strength metric        exceeds a corresponding at least one predetermined threshold;        and    -   increase the at least one of the fraction of the full bandwidth        or the fraction of the full number of repetitions to receive the        PRS when the at least one signal strength metric does not exceed        the corresponding at least one predetermined threshold for the        predetermined number of beams.    -   20. The mobile device of clause 19, wherein the at least one        processor is further configured to iteratively increase the at        least one of the fraction of the full bandwidth or the fraction        of the full number of repetitions to receive the PRS and        determine whether the at least one signal strength metric        exceeds the corresponding at least one predetermined threshold        until the at least one signal strength metric exceeds the        corresponding at least one predetermined threshold for the        predetermined number of beams.    -   21. The mobile device of any of clauses 13-18, wherein the        predetermined number of beams are selected based on at least one        signal strength metric of each beam, and wherein the at least        one processor is further configured to:    -   select at least one of a fraction of the full bandwidth or a        fraction of the full number of repetitions to receive the PRS;    -   determine whether the at least one signal strength metric        exceeds a corresponding at least one predetermined threshold;        and    -   select the predetermined number of beams for receiving when the        at least one signal strength metric exceeds the corresponding at        least one predetermined threshold for more than the        predetermined number of beams.    -   22. The mobile device of clause 21, wherein the at least one        processor is further configured to decrease the at least one of        the fraction of the full bandwidth or the fraction of the full        number of repetitions to receive the PRS in a subsequent        positioning occasion.    -   23. The mobile device of any of clauses 13-22, wherein the at        least one processor is further configured to:    -   receive, using the wireless transceiver, the PRS from the        selected beams using the full set of resources for the PRS        produce by each selected beam for multiple positioning        occasions;    -   determine a difference in at least one signal strength metric        between two positioning occasions for one or more selected beams        is below a predetermined threshold; and    -   receive, using the wireless transceiver, the PRS transmitted in        the plurality of beams using less than the full set of resources        for the PRS produced by each beam after determining the        difference is below the predetermined threshold.    -   24. The mobile device of any of clauses 13-22, wherein the at        least one processor is further configured to:    -   receive, using the wireless transceiver, the PRS from the        selected beams using the full set of resources for the PRS        produce by each selected beam for a predetermined number of        positioning occasions; and    -   receive, using the wireless transceiver, the PRS transmitted in        the plurality of beams using less than the full set of resources        for the PRS produced by each beam after the predetermined number        of positioning occasions.    -   25. A mobile device configured for supporting positioning of the        mobile device in a wireless network, comprising:    -   means for receiving positioning reference signals (PRS)        transmitted in a plurality of beams from a base station using        less than a full set of resources for the PRS produced by each        beam, wherein less than the full set of resources for the PRS        comprises less than a full bandwidth, less than a full number of        repetitions in a positioning occasion, or a combination thereof;    -   means for selecting a predetermined number of beams from the        plurality of beams; and    -   means for receiving the PRS from the selected beams using the        full set of resources for the PRS produced by each selected        beam.    -   26. The mobile device of clause 25, wherein the means for        receiving the PRS using less than the full set of resources for        the PRS produced by each beam comprises a means for selecting a        fraction of the full bandwidth and means for tuning to receive        radio signals on the fraction of the full bandwidth, and wherein        the means for receiving the PRS from the selected beams using        the full set of resources for the PRS produced by each selected        beam comprises means for tuning to receive radio signals on the        full bandwidth.    -   27. The mobile device of either of clauses 25 or 26, wherein the        means for receiving the PRS using less than the full set of        resources for the PRS produced by each beam comprises means for        selecting a fraction of the full number of repetitions for the        PRS and means for integrating over only the fraction of the full        number of repetitions to receive the PRS, and wherein the means        for receiving the PRS from the selected beams using the full set        of resources for the PRS produced by each selected beam        comprises means for integrating over full number of repetitions        to receive the PRS.    -   28. A non-transitory computer readable storage medium including        program code stored thereon, the program code is operable to        configure at least one processor in a mobile device for        supporting positioning of the mobile device in a wireless        network, comprising:    -   program code to receive positioning reference signals (PRS)        transmitted in a plurality of beams from a base station using        less than a full set of resources for the PRS produced by each        beam, wherein less than the full set of resources for the PRS        comprises less than a full bandwidth, less than a full number of        repetitions in a positioning occasion, or a combination thereof;    -   program code to select a predetermined number of beams from the        plurality of beams; and    -   program code to receive the PRS from the selected beams using        the full set of resources for the PRS produced by each selected        beam.    -   29. The non-transitory computer readable storage medium of        clause 28, wherein the program code to receive the PRS using        less than the full set of resources for the PRS produced by each        beam selects a fraction of the full bandwidth and tunes a        wireless transceiver to receive radio signals on the fraction of        the full bandwidth, and wherein the program code to receive the        PRS from the selected beams using the full set of resources for        the PRS produced by each selected beam tunes the wireless        transceiver to receive radio signals on the full bandwidth.    -   30. The non-transitory computer readable storage medium of        either of clauses 28 or 29, wherein the program code to receive        the PRS using less than the full set of resources for the PRS        produced by each beam selects a fraction of the full number of        repetitions for the PRS and integrates over only the fraction of        the full number of repetitions to receive the PRS, and wherein        the program code to receive the PRS from the selected beams        using the full set of resources for the PRS produced by each        selected beam integrates over full number of repetitions to        receive the PRS.    -   Although the present disclosure is described in connection with        specific embodiments for instructional purposes, the disclosure        is not limited thereto. Various adaptations and modifications        may be made to the disclosure without departing from the scope.        Therefore, the spirit and scope of the appended claims should        not be limited to the foregoing description.

1. A method for supporting positioning of a mobile device in a wirelessnetwork performed by the mobile device, the method comprising: receivingpositioning reference signals (PRS) transmitted in a plurality of beamsfrom a base station, wherein less than a full set of resources for thePRS in each beam is used to receive the PRS; selecting a predeterminednumber of beams from the plurality of beams; and receiving the PRS fromthe selected beams using the full set of resources for the PRS producedby each selected beam.
 2. The method of claim 1, wherein less than thefull set of resources for the PRS comprises at least one of: less than afull bandwidth for the PRS, or less than a full number of repetitions ofthe PRS in a positioning occasion.
 3. The method of claim 1, wherein thePRS has a comb structure and a periodicity.
 4. The method of claim 3,wherein the comb structure comprises a comb-2 structure with 2 symbols,a comb-4 structure with 4 symbols, a comb-6 structure with 6 symbols, ora comb-12 structure with 12 symbols.
 5. The method of claim 1, furthercomprising: performing the positioning of the mobile device using thereceived PRS from the selected beams.
 6. The method of claim 1, whereinreceiving the PRS comprises selecting a fraction of a full bandwidth ofeach beam and tuning to receive radio signals on the fraction of thefull bandwidth, and wherein receiving the PRS from the selected beamsusing the full set of resources for the PRS produced by each selectedbeam comprises tuning to receive the radio signals on the fullbandwidth.
 7. The method of claim 1, wherein receiving the PRS comprisesselecting a fraction of a full number of repetitions for the PRS in apositioning occasion and integrating over only the fraction of the fullnumber of repetitions to receive the PRS, and wherein receiving the PRSfrom the selected beams using the full set of resources for the PRSproduced by each selected beam comprises integrating over the fullnumber of repetitions to receive the PRS.
 8. The method of claim 1,wherein selecting the predetermined number of beams comprises:determining at least one signal strength metric for each beam in theplurality of beams; comparing the at least one signal strength metric toa corresponding at least one predetermined threshold; and selecting thepredetermined number of beams based on the comparison of the at leastone signal strength metric to the corresponding at least onepredetermined threshold.
 9. The method of claim 1, wherein thepredetermined number of beams are selected based on at least one signalstrength metric of each beam, and wherein the method further comprises:selecting a fraction of the full set of resources for the PRS to receivethe PRS; determining whether the at least one signal strength metricexceeds a corresponding at least one predetermined threshold; andincreasing the fraction of the full set of resources for the PRS toreceive the PRS when the at least one signal strength metric does notexceed the corresponding at least one predetermined threshold for thepredetermined number of beams.
 10. The method of claim 9, furthercomprising: iteratively increasing at least one of a fraction of a fullbandwidth or a fraction of a full number of repetitions to receive thePRS; and determining whether the at least one signal strength metricexceeds the corresponding at least one predetermined threshold until theat least one signal strength metric exceeds the corresponding at leastone predetermined threshold for the predetermined number of beams. 11.The method of claim 1, wherein the predetermined number of beams areselected based on at least one signal strength metric of each beam, andwherein the method further comprises: selecting a fraction of the fullset of resources for the PRS to receive the PRS; determining whether theat least one signal strength metric exceeds a corresponding at least onepredetermined threshold; and selecting the predetermined number of beamsfor receiving when the at least one signal strength metric exceeds thecorresponding at least one predetermined threshold for more than thepredetermined number of beams.
 12. The method of claim 11, the methodfurther comprising: decreasing the at least one of a fraction of a fullbandwidth or a fraction of a full number of repetitions to receive thePRS in a subsequent positioning occasion.
 13. The method of claim 1,further comprising: receiving the PRS from the selected beams using thefull set of resources for the PRS produce by each selected beam formultiple positioning occasions; determining a difference in at least onesignal strength metric between two positioning occasions for one or moreselected beams is below a predetermined threshold; and receiving the PRStransmitted in the plurality of beams using less than the full set ofresources for the PRS produced by each beam after determining thedifference is below the predetermined threshold.
 14. The method of claim1, further comprising: receiving the PRS from the selected beams usingthe full set of resources for the PRS produce by each selected beam fora predetermined number of positioning occasions; and receiving the PRStransmitted in the plurality of beams using less than the full set ofresources for the PRS produced by each beam after the predeterminednumber of positioning occasions.
 15. A mobile device configured forsupporting positioning of the mobile device in a wireless network,comprising: a wireless transceiver configured to wirelessly communicatein the wireless network; at least one memory; at least one processorcoupled to the wireless transceiver and the at least one memory, whereinthe at least one processor is configured to: receive, using the wirelesstransceiver, positioning reference signals (PRS) transmitted in aplurality of beams from a base station, wherein less than a full set ofresources for the PRS in each beam is used to receive the PRS; select apredetermined number of beams from the plurality of beams; and receive,using the wireless transceiver, the PRS from the selected beams usingthe full set of resources for the PRS produced by each selected beam.16. The mobile device of claim 15, wherein less than the full set ofresources for the PRS comprises at least one of: less than a fullbandwidth for the PRS, or less than a full number of repetitions of thePRS in a positioning occasion.
 17. The mobile device of claim 15,wherein the PRS has a comb structure and a periodicity.
 18. The mobiledevice of claim 17, wherein the comb structure comprises a comb-2structure with 2 symbols, a comb-4 structure with 4 symbols, a comb-6structure with 6 symbols, or a comb-12 structure with 12 symbols. 19.The mobile device of claim 15, wherein the at least one processor isfurther configured to: perform the positioning of the mobile deviceusing the received PRS from the selected beams.
 20. The mobile device ofclaim 15, wherein the at least one processor is configured to receivethe PRS by being configured to select a fraction of a full bandwidth ofeach beam and tune the wireless transceiver to receive radio signals onthe fraction of the full bandwidth, and wherein the at least oneprocessor is configured to receive the PRS from the selected beams usingthe full set of resources for the PRS produced by each selected beam bybeing configured to tune the wireless transceiver to receive the radiosignals on the full bandwidth.
 21. The mobile device of claim 15,wherein the at least one processor is configured to receive the PRS bybeing configured to select a fraction of a full number of repetitionsfor the PRS in a positioning occasion and integrate over only thefraction of the full number of repetitions to receive the PRS, andwherein the at least one processor is configured to receive the PRS fromthe selected beams using the full set of resources for the PRS producedby each selected beam by being configured to integrate over the fullnumber of repetitions to receive the PRS.
 22. The mobile device of claim15, wherein the at least one processor is configured to select thepredetermined number of beams by being configured to: determine at leastone signal strength metric for each beam in the plurality of beams;compare the at least one signal strength metric to a corresponding atleast one predetermined threshold; and select the predetermined numberof beams based on the comparison of the at least one signal strengthmetric to the corresponding at least one predetermined threshold. 23.The mobile device of claim 15, wherein the predetermined number of beamsare selected based on at least one signal strength metric of each beam,and wherein the at least one processor is further configured to: selecta fraction of the full set of resources for the PRS to receive the PRS;determine whether the at least one signal strength metric exceeds acorresponding at least one predetermined threshold; and increase thefraction of the full set of resources for the PRS to receive the PRSwhen the at least one signal strength metric does not exceed thecorresponding at least one predetermined threshold for the predeterminednumber of beams.
 24. The mobile device of claim 23, wherein the at leastone processor is further configured to: iteratively increase the atleast one of a fraction of a full bandwidth or a fraction of a fullnumber of repetitions to receive the PRS; and determine whether the atleast one signal strength metric exceeds the corresponding at least onepredetermined threshold until the at least one signal strength metricexceeds the corresponding at least one predetermined threshold for thepredetermined number of beams.
 25. The mobile device of claim 15,wherein the predetermined number of beams are selected based on at leastone signal strength metric of each beam, and wherein the at least oneprocessor is further configured to: select a fraction of the full set ofresources for the PRS to receive the PRS; determine whether the at leastone signal strength metric exceeds a corresponding at least onepredetermined threshold; and select the predetermined number of beamsfor receiving when the at least one signal strength metric exceeds thecorresponding at least one predetermined threshold for more than thepredetermined number of beams.
 26. The mobile device of claim 25,wherein the at least one processor is further configured to: decreasethe at least one of a fraction of a full bandwidth or a fraction of afull number of repetitions to receive the PRS in a subsequentpositioning occasion.
 27. The mobile device of claim 15, wherein the atleast one processor is further configured to: receive, using thewireless transceiver, the PRS from the selected beams using the full setof resources for the PRS produce by each selected beam for multiplepositioning occasions; determine a difference in at least one signalstrength metric between two positioning occasions for one or moreselected beams is below a predetermined threshold; and receive, usingthe wireless transceiver, the PRS transmitted in the plurality of beamsusing less than the full set of resources for the PRS produced by eachbeam after a determination that the difference is below thepredetermined threshold.
 28. The mobile device of claim 15, wherein theat least one processor is further configured to: receive, using thewireless transceiver, the PRS from the selected beams using the full setof resources for the PRS produce by each selected beam for apredetermined number of positioning occasions; and receive, using thewireless transceiver, the PRS transmitted in the plurality of beamsusing less than the full set of resources for the PRS produced by eachbeam after the predetermined number of positioning occasions.
 29. Amobile device configured for supporting positioning of the mobile devicein a wireless network, comprising: means for receiving positioningreference signals (PRS) transmitted in a plurality of beams from a basestation, wherein less than a full set of resources for the PRS in eachbeam is used to receive the PRS; means for selecting a predeterminednumber of beams from the plurality of beams; and means for receiving thePRS from the selected beams using the full set of resources for the PRSproduced by each selected beam.
 30. A non-transitory computer readablestorage medium including program code stored thereon, the program codeis operable to configure at least one processor in a mobile device forsupporting positioning of the mobile device in a wireless network,comprising: program code to receive positioning reference signals (PRS)transmitted in a plurality of beams from a base station, wherein lessthan a full set of resources for the PRS in each beam is used to receivethe PRS; program code to select a predetermined number of beams from theplurality of beams; and program code to receive the PRS from theselected beams using the full set of resources for the PRS produced byeach selected beam.